From 89a78cb5d9b17a7b840c3d8de465dff4bafcee39 Mon Sep 17 00:00:00 2001
From: Jan Krňávek <Jan.Krnavek@gmail.com>
Date: Sat, 23 Oct 2021 15:59:05 +0200
Subject: 1-Z needs 36 base

---
 challenge-135/wambash/raku/ch-2.raku | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/challenge-135/wambash/raku/ch-2.raku b/challenge-135/wambash/raku/ch-2.raku
index d8fe6da3c8..721c149ae2 100644
--- a/challenge-135/wambash/raku/ch-2.raku
+++ b/challenge-135/wambash/raku/ch-2.raku
@@ -24,7 +24,7 @@ class Validate-SEDOL {
     }
 
     method char ($/) {
-        make $/.Str.parse-base(35)
+        make $/.Str.parse-base(36)
     }
 }
 
-- 
cgit 


From baad1c27d1e0f4945733ad51fb5fb10694f55540 Mon Sep 17 00:00:00 2001
From: Dave Jacoby <jacoby.david@gmail.com>
Date: Mon, 25 Oct 2021 19:21:45 -0400
Subject: Challenge 136

---
 challenge-136/dave-jacoby/blog.txt     |  1 +
 challenge-136/dave-jacoby/perl/ch-1.pl | 38 +++++++++++++++++++
 challenge-136/dave-jacoby/perl/ch-2.pl | 67 ++++++++++++++++++++++++++++++++++
 3 files changed, 106 insertions(+)
 create mode 100644 challenge-136/dave-jacoby/blog.txt
 create mode 100644 challenge-136/dave-jacoby/perl/ch-1.pl
 create mode 100644 challenge-136/dave-jacoby/perl/ch-2.pl

diff --git a/challenge-136/dave-jacoby/blog.txt b/challenge-136/dave-jacoby/blog.txt
new file mode 100644
index 0000000000..4820c56511
--- /dev/null
+++ b/challenge-136/dave-jacoby/blog.txt
@@ -0,0 +1 @@
+https://jacoby.github.io/2021/10/25/the-sequential-friendly-book-the-weekly-challenge-136.html
diff --git a/challenge-136/dave-jacoby/perl/ch-1.pl b/challenge-136/dave-jacoby/perl/ch-1.pl
new file mode 100644
index 0000000000..67eece6bc7
--- /dev/null
+++ b/challenge-136/dave-jacoby/perl/ch-1.pl
@@ -0,0 +1,38 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use feature qw{ say state postderef signatures };
+no warnings qw{ experimental };
+
+my @examples = ( [ 8, 24 ], [ 26, 39 ], [ 4, 10 ], [ 24, 40 ] );
+
+for my $i (@examples) {
+    my ( $m, $n ) = $i->@*;
+    my $o = two_friendly( $i->@* );
+    say <<"END";
+    Input: \$m = $m \$n = $n
+    Output: $o
+END
+}
+
+# "Two-Friendly" means the greatest common
+# denominator is a power of two.
+
+# Greatest common denomonator is the product
+# of all the common denominators. 
+
+# So, the moment you get a common denominator 
+# that is NOT zero, you have a two-unfriendly
+# number and can securely return 0
+sub two_friendly ( $m = 8, $n = 16 ) {
+    my ($lower) = sort { $a <=> $b } $m, $n;
+    for my $i ( 2 .. $lower ) {
+        while ( $m % $i == 0 && $n % $i == 0 ) {
+            $m /= $i;
+            $n /= $i;
+            return 0 if $i != 2;
+        }
+    }
+    return 1;
+}
diff --git a/challenge-136/dave-jacoby/perl/ch-2.pl b/challenge-136/dave-jacoby/perl/ch-2.pl
new file mode 100644
index 0000000000..57f66a430a
--- /dev/null
+++ b/challenge-136/dave-jacoby/perl/ch-2.pl
@@ -0,0 +1,67 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use feature qw{ say postderef signatures state };
+no warnings qw{ experimental };
+
+use JSON;
+use List::Util qw{ sum0 uniq };
+my $json = JSON->new->pretty->canonical;
+
+my @examples = qw{16 9 15};
+
+for my $n (@examples) {
+    my @o  = solve_task($n);
+    my $o  = scalar @o;
+    my $oo = join ",\n        ", map { ($_) } @o;
+
+    say <<"END";
+    Input: \$n = $n
+    Output: $o
+        $oo
+END
+}
+
+sub solve_task ($n) {
+    my @fib       = grep { $_ < $n } map { fib($_) } 1 .. $n;
+    my @sequences = recursion( $n, \@fib );
+    return @sequences;
+}
+
+# Let's call it what it is
+sub recursion ( $n, $ref, $x = [] ) {
+    my @output;
+    my $depth   = 1 + scalar $x->@*;
+    my $sum     = sum0 $x->@*;
+    my $nex->@* = sort $ref->@*;
+
+    return undef if $sum > $n;
+
+    if ( $sum == $n ) {
+        $x->@* = sort { $a <=> $b } map { int $_ } $x->@*;
+        my $answer = join ' + ', $x->@*;
+        return $answer;
+    }
+
+    for my $i ( 1 .. scalar $nex->@* ) {
+        my $v = shift $nex->@*;
+        my $y->@* = $x->@*;
+        push $y->@*, $v;
+
+        my @return = recursion( $n, $nex, $y );
+        push @output, @return;
+        push $nex->@*, $v;
+    }
+    return uniq sort grep { defined } @output;
+}
+
+sub fib ($n) {
+    state $fib;
+    $fib->{0} = 1;
+    $fib->{1} = 1;
+    if ( $fib->{$n} ) {
+        return $fib->{$n};
+    }
+    $fib->{$n} = fib( $n - 1 ) + fib( $n - 2 );
+}
-- 
cgit 


From 1c83475aade8956c9ef0de26484981e6e93d73fa Mon Sep 17 00:00:00 2001
From: Paulo Custodio <pauloscustodio@gmail.com>
Date: Fri, 29 Oct 2021 10:55:09 +0100
Subject: Add Perl and Pyhton solutions to challenge 122

---
 challenge-001/paulo-custodio/brainfuck/ch-2.pl | 24 +++++------
 challenge-122/paulo-custodio/Makefile          |  2 +
 challenge-122/paulo-custodio/perl/ch-1.pl      | 26 ++++++++++++
 challenge-122/paulo-custodio/perl/ch-2.pl      | 55 ++++++++++++++++++++++++++
 challenge-122/paulo-custodio/python/ch-1.py    | 25 ++++++++++++
 challenge-122/paulo-custodio/python/ch-2.py    | 52 ++++++++++++++++++++++++
 challenge-122/paulo-custodio/t/test-1.yaml     | 23 +++++++++++
 challenge-122/paulo-custodio/t/test-2.yaml     | 30 ++++++++++++++
 8 files changed, 225 insertions(+), 12 deletions(-)
 create mode 100644 challenge-122/paulo-custodio/Makefile
 create mode 100644 challenge-122/paulo-custodio/perl/ch-1.pl
 create mode 100644 challenge-122/paulo-custodio/perl/ch-2.pl
 create mode 100644 challenge-122/paulo-custodio/python/ch-1.py
 create mode 100644 challenge-122/paulo-custodio/python/ch-2.py
 create mode 100644 challenge-122/paulo-custodio/t/test-1.yaml
 create mode 100644 challenge-122/paulo-custodio/t/test-2.yaml

diff --git a/challenge-001/paulo-custodio/brainfuck/ch-2.pl b/challenge-001/paulo-custodio/brainfuck/ch-2.pl
index 7ef784110a..65b62fd55a 100644
--- a/challenge-001/paulo-custodio/brainfuck/ch-2.pl
+++ b/challenge-001/paulo-custodio/brainfuck/ch-2.pl
@@ -14,18 +14,18 @@ use Modern::Perl;
 
 my $text = "";
 for my $n (1..20) {
-	if ($n%15==0) {
-		$text .= "fizzbuzz\n";
-	}
-	elsif ($n%3==0) {
-		$text .= "fizz\n";
-	}
-	elsif ($n%5==0) {
-		$text .= "buzz\n";
-	}
-	else {
-		$text .= "$n\n";
-	}
+    if ($n%15==0) {
+        $text .= "fizzbuzz\n";
+    }
+    elsif ($n%3==0) {
+        $text .= "fizz\n";
+    }
+    elsif ($n%5==0) {
+        $text .= "buzz\n";
+    }
+    else {
+        $text .= "$n\n";
+    }
 }
 
 for (split //, $text) {
diff --git a/challenge-122/paulo-custodio/Makefile b/challenge-122/paulo-custodio/Makefile
new file mode 100644
index 0000000000..6316089eb8
--- /dev/null
+++ b/challenge-122/paulo-custodio/Makefile
@@ -0,0 +1,2 @@
+all: 
+	perl ../../challenge-001/paulo-custodio/test.pl
diff --git a/challenge-122/paulo-custodio/perl/ch-1.pl b/challenge-122/paulo-custodio/perl/ch-1.pl
new file mode 100644
index 0000000000..ea7ea0371a
--- /dev/null
+++ b/challenge-122/paulo-custodio/perl/ch-1.pl
@@ -0,0 +1,26 @@
+#!/usr/bin/env perl
+
+# TASK #1 > Average of Stream
+# Submitted by: Mohammad S Anwar
+# You are given a stream of numbers, @N.
+#
+# Write a script to print the average of the stream at every point.
+#
+# Example
+# Input: @N = (10, 20, 30, 40, 50, 60, 70, 80, 90, ...)
+# Output:      10, 15, 20, 25, 30, 35, 40, 45, 50, ...
+#
+# Average of first number is 10.
+# Average of first 2 numbers (10+20)/2 = 15
+# Average of first 3 numbers (10+20+30)/3 = 20
+# Average of first 4 numbers (10+20+30+40)/4 = 25 and so on.
+
+use Modern::Perl;
+
+my $sum = 0;
+my $count = 0;
+while (<>) {
+    $sum += $_;
+    $count++;
+    say sprintf("%.2f", $sum/$count);
+}
diff --git a/challenge-122/paulo-custodio/perl/ch-2.pl b/challenge-122/paulo-custodio/perl/ch-2.pl
new file mode 100644
index 0000000000..de1bfb1ee4
--- /dev/null
+++ b/challenge-122/paulo-custodio/perl/ch-2.pl
@@ -0,0 +1,55 @@
+#!/usr/bin/env perl
+
+# TASK #2 > Basketball Points
+# Submitted by: Mohammad S Anwar
+# You are given a score $S.
+#
+# You can win basketball points e.g. 1 point, 2 points and 3 points.
+#
+# Write a script to find out the different ways you can score $S.
+#
+# Example
+# Input: $S = 4
+# Output: 1 1 1 1
+#         1 1 2
+#         1 2 1
+#         1 3
+#         2 1 1
+#         2 2
+#         3 1
+#
+# Input: $S = 5
+# Output: 1 1 1 1 1
+#         1 1 1 2
+#         1 1 2 1
+#         1 1 3
+#         1 2 1 1
+#         1 2 2
+#         1 3 1
+#         2 1 1 1
+#         2 1 2
+#         2 2 1
+#         2 3
+#         3 1 1
+#         3 2
+
+use Modern::Perl;
+use List::Util 'sum';
+
+my $N = shift||0;
+show_scores($N);
+
+sub show_scores {
+    my($N, @points) = @_;
+    my $s = @points ? sum(@points) : 0;
+    if ($s > $N) {
+    }
+    elsif ($s == $N) {
+        say "@points";
+    }
+    else {
+        show_scores($N, @points, 1);
+        show_scores($N, @points, 2);
+        show_scores($N, @points, 3);
+    }
+}
diff --git a/challenge-122/paulo-custodio/python/ch-1.py b/challenge-122/paulo-custodio/python/ch-1.py
new file mode 100644
index 0000000000..ab54b706fa
--- /dev/null
+++ b/challenge-122/paulo-custodio/python/ch-1.py
@@ -0,0 +1,25 @@
+#!/usr/bin/env python3
+
+# TASK #1 > Average of Stream
+# Submitted by: Mohammad S Anwar
+# You are given a stream of numbers, @N.
+#
+# Write a script to print the average of the stream at every point.
+#
+# Example
+# Input: @N = (10, 20, 30, 40, 50, 60, 70, 80, 90, ...)
+# Output:      10, 15, 20, 25, 30, 35, 40, 45, 50, ...
+#
+# Average of first number is 10.
+# Average of first 2 numbers (10+20)/2 = 15
+# Average of first 3 numbers (10+20+30)/3 = 20
+# Average of first 4 numbers (10+20+30+40)/4 = 25 and so on.
+
+import sys
+
+sum = 0
+count = 0
+for line in sys.stdin:
+    sum += int(line)
+    count += 1
+    print("{:.2f}".format(sum/count))
diff --git a/challenge-122/paulo-custodio/python/ch-2.py b/challenge-122/paulo-custodio/python/ch-2.py
new file mode 100644
index 0000000000..0556080767
--- /dev/null
+++ b/challenge-122/paulo-custodio/python/ch-2.py
@@ -0,0 +1,52 @@
+#!/usr/bin/env python3
+
+# TASK #2 > Basketball Points
+# Submitted by: Mohammad S Anwar
+# You are given a score $S.
+#
+# You can win basketball points e.g. 1 point, 2 points and 3 points.
+#
+# Write a script to find out the different ways you can score $S.
+#
+# Example
+# Input: $S = 4
+# Output: 1 1 1 1
+#         1 1 2
+#         1 2 1
+#         1 3
+#         2 1 1
+#         2 2
+#         3 1
+#
+# Input: $S = 5
+# Output: 1 1 1 1 1
+#         1 1 1 2
+#         1 1 2 1
+#         1 1 3
+#         1 2 1 1
+#         1 2 2
+#         1 3 1
+#         2 1 1 1
+#         2 1 2
+#         2 2 1
+#         2 3
+#         3 1 1
+#         3 2
+
+import sys
+
+def show_scores(N):
+    def scores(N, points):
+        s = sum(points)
+        if s > N:
+            pass
+        elif s == N:
+            print(" ".join([str(x) for x in points]))
+        else:
+            scores(N, [*points, 1])
+            scores(N, [*points, 2])
+            scores(N, [*points, 3])
+    scores(N, [])
+
+N = int(sys.argv[1])
+show_scores(N)
diff --git a/challenge-122/paulo-custodio/t/test-1.yaml b/challenge-122/paulo-custodio/t/test-1.yaml
new file mode 100644
index 0000000000..e62a1cd366
--- /dev/null
+++ b/challenge-122/paulo-custodio/t/test-1.yaml
@@ -0,0 +1,23 @@
+- setup:
+  cleanup:
+  args:
+  input:    |
+            10
+            20
+            30
+            40
+            50
+            60
+            70
+            80
+            90
+  output:   |
+            10.00
+            15.00
+            20.00
+            25.00
+            30.00
+            35.00
+            40.00
+            45.00
+            50.00
diff --git a/challenge-122/paulo-custodio/t/test-2.yaml b/challenge-122/paulo-custodio/t/test-2.yaml
new file mode 100644
index 0000000000..df6bd41cc9
--- /dev/null
+++ b/challenge-122/paulo-custodio/t/test-2.yaml
@@ -0,0 +1,30 @@
+- setup:
+  cleanup:
+  args:     4
+  input:
+  output:   |
+            1 1 1 1
+            1 1 2
+            1 2 1
+            1 3
+            2 1 1
+            2 2
+            3 1
+- setup:
+  cleanup:
+  args:     5
+  input:
+  output:   |
+            1 1 1 1 1
+            1 1 1 2
+            1 1 2 1
+            1 1 3
+            1 2 1 1
+            1 2 2
+            1 3 1
+            2 1 1 1
+            2 1 2
+            2 2 1
+            2 3
+            3 1 1
+            3 2
-- 
cgit 


From 3942303512e3ac0e48e57a2e9e8c2ef2a5e8cb6e Mon Sep 17 00:00:00 2001
From: Paulo Custodio <pauloscustodio@gmail.com>
Date: Fri, 29 Oct 2021 13:39:49 +0100
Subject: Add Python solutions to challenge 121

---
 challenge-121/paulo-custodio/Makefile       |  2 +
 challenge-121/paulo-custodio/python/ch-1.py | 30 +++++++++++++++
 challenge-121/paulo-custodio/python/ch-2.py | 57 +++++++++++++++++++++++++++++
 challenge-121/paulo-custodio/test.pl        |  4 --
 4 files changed, 89 insertions(+), 4 deletions(-)
 create mode 100644 challenge-121/paulo-custodio/Makefile
 create mode 100644 challenge-121/paulo-custodio/python/ch-1.py
 create mode 100644 challenge-121/paulo-custodio/python/ch-2.py
 delete mode 100644 challenge-121/paulo-custodio/test.pl

diff --git a/challenge-121/paulo-custodio/Makefile b/challenge-121/paulo-custodio/Makefile
new file mode 100644
index 0000000000..6316089eb8
--- /dev/null
+++ b/challenge-121/paulo-custodio/Makefile
@@ -0,0 +1,2 @@
+all: 
+	perl ../../challenge-001/paulo-custodio/test.pl
diff --git a/challenge-121/paulo-custodio/python/ch-1.py b/challenge-121/paulo-custodio/python/ch-1.py
new file mode 100644
index 0000000000..c4f5276926
--- /dev/null
+++ b/challenge-121/paulo-custodio/python/ch-1.py
@@ -0,0 +1,30 @@
+#!/usr/bin/env python3
+
+# Challenge 121
+#
+# TASK #1 > Invert Bit
+# Submitted by: Mohammad S Anwar
+# You are given integers 0 <= $m <= 255 and 1 <= $n <= 8.
+#
+# Write a script to invert $n bit from the end of the binary representation of
+# $m and print the decimal representation of the new binary number.
+#
+# Example
+# Input: $m = 12, $n = 3
+# Output: 8
+#
+# Binary representation of $m = 00001100
+# Invert 3rd bit from the end = 00001000
+# Decimal equivalent of 00001000 = 8
+#
+# Input $m = 18, $n = 4
+# Output: 26
+#
+# Binary representation of $m = 00010010
+# Invert 4th bit from the end = 00011010
+# Decimal equivalent of 00011010 = 26
+
+import sys
+
+m, n = int(sys.argv[1]), int(sys.argv[2])
+print(m ^ (1 << (n-1)))
diff --git a/challenge-121/paulo-custodio/python/ch-2.py b/challenge-121/paulo-custodio/python/ch-2.py
new file mode 100644
index 0000000000..7a3b6f4443
--- /dev/null
+++ b/challenge-121/paulo-custodio/python/ch-2.py
@@ -0,0 +1,57 @@
+#!/usr/bin/env python3
+
+# Challenge 121
+#
+# TASK #2 > The Travelling Salesman
+# Submitted by: Jorg Sommrey
+# You are given a NxN matrix containing the distances between N cities.
+#
+# Write a script to find a round trip of minimum length visiting all N cities
+# exactly once and returning to the start.
+#
+# Example
+# Matrix: [0, 5, 2, 7]
+#         [5, 0, 5, 3]
+#         [3, 1, 0, 6]
+#         [4, 5, 4, 0]
+#
+# Output:
+#         length = 10
+#         tour = (0 2 1 3 0)
+
+import sys
+
+def read_dist():
+    dist = []
+    for line in sys.stdin:
+        row = [int(x) for x in line.split()]
+        dist.append(row)
+    return dist
+
+def shortest_tour(dist):
+    short_length = 100000
+    short_path = []
+
+    def tour(length, path):
+        nonlocal short_length, short_path
+
+        cities = list(set(range(0, len(dist))) - set(path))
+        cities.sort()
+
+        if len(cities)==0:
+            # no more cities to visit
+            length += dist[path[-1]][path[0]]
+            path.append(path[0])
+            if length < short_length:
+                short_length, short_path = length, path
+        else:
+            # try each city
+            for city in cities:
+                tour(length + dist[path[-1]][city], [*path, city])
+
+    tour(0, [0])
+    return (short_length, short_path)
+
+length, path = shortest_tour(read_dist())
+print("length =", length)
+print("tour = ("+ " ".join([str(x) for x in path]) + ")")
diff --git a/challenge-121/paulo-custodio/test.pl b/challenge-121/paulo-custodio/test.pl
deleted file mode 100644
index ba6c37260b..0000000000
--- a/challenge-121/paulo-custodio/test.pl
+++ /dev/null
@@ -1,4 +0,0 @@
-#!/usr/bin/env perl
-use Modern::Perl;
-use Test::More;
-require '../../challenge-001/paulo-custodio/test.pl';
-- 
cgit 


From f58e9e88056887a42482592154c1c7cbe03e61cb Mon Sep 17 00:00:00 2001
From: Paulo Custodio <pauloscustodio@gmail.com>
Date: Fri, 29 Oct 2021 14:40:28 +0100
Subject: Fix 64-bit portability

---
 challenge-118/paulo-custodio/d/ch_2.d | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/challenge-118/paulo-custodio/d/ch_2.d b/challenge-118/paulo-custodio/d/ch_2.d
index 122b253812..eed57ac24d 100644
--- a/challenge-118/paulo-custodio/d/ch_2.d
+++ b/challenge-118/paulo-custodio/d/ch_2.d
@@ -227,7 +227,7 @@ Move[] next_moves(Game* game) {
     for (int i = 0; i < moves.length; i++) {
         Move[] temp_moves;
         try_num_moves(&temp_moves, game, moves[i].row, moves[i].col);
-        moves[i].num_moves = temp_moves.length;
+        moves[i].num_moves = cast(int)temp_moves.length;
         if (min_moves > moves[i].num_moves) min_moves = moves[i].num_moves;
     }
 
-- 
cgit 


From bf8032b503c262609b9b77e60ed56864a4546aed Mon Sep 17 00:00:00 2001
From: Paulo Custodio <pauloscustodio@gmail.com>
Date: Fri, 29 Oct 2021 14:41:00 +0100
Subject: Add Python solution

---
 challenge-118/paulo-custodio/Makefile       |  2 ++
 challenge-118/paulo-custodio/python/ch-1.py | 27 +++++++++++++++++++++++++++
 challenge-118/paulo-custodio/test.pl        |  4 ----
 3 files changed, 29 insertions(+), 4 deletions(-)
 create mode 100644 challenge-118/paulo-custodio/Makefile
 create mode 100644 challenge-118/paulo-custodio/python/ch-1.py
 delete mode 100644 challenge-118/paulo-custodio/test.pl

diff --git a/challenge-118/paulo-custodio/Makefile b/challenge-118/paulo-custodio/Makefile
new file mode 100644
index 0000000000..c3c762d746
--- /dev/null
+++ b/challenge-118/paulo-custodio/Makefile
@@ -0,0 +1,2 @@
+all:
+	perl ../../challenge-001/paulo-custodio/test.pl
diff --git a/challenge-118/paulo-custodio/python/ch-1.py b/challenge-118/paulo-custodio/python/ch-1.py
new file mode 100644
index 0000000000..b7652634d3
--- /dev/null
+++ b/challenge-118/paulo-custodio/python/ch-1.py
@@ -0,0 +1,27 @@
+#!/usr/bin/env python3
+
+# Challenge 118
+#
+# TASK #1 - Binary Palindrome
+# Submitted by: Mohammad S Anwar
+# You are given a positive integer $N.
+#
+# Write a script to find out if the binary representation of the given integer
+# is Palindrome. Print 1 if it is otherwise 0.
+#
+# Example
+# Input: $N = 5
+# Output: 1 as binary representation of 5 is 101 which is Palindrome.
+#
+# Input: $N = 4
+# Output: 0 as binary representation of 4 is 100 which is NOT Palindrome.
+
+import sys
+
+N = int(sys.argv[1])
+bits = "{:b}".format(N)
+rbits = bits[::-1]
+if bits==rbits:
+    print(1)
+else:
+    print(0)
diff --git a/challenge-118/paulo-custodio/test.pl b/challenge-118/paulo-custodio/test.pl
deleted file mode 100644
index ba6c37260b..0000000000
--- a/challenge-118/paulo-custodio/test.pl
+++ /dev/null
@@ -1,4 +0,0 @@
-#!/usr/bin/env perl
-use Modern::Perl;
-use Test::More;
-require '../../challenge-001/paulo-custodio/test.pl';
-- 
cgit 


From 4a2405f3765c0c9494656c716a03d39075fce490 Mon Sep 17 00:00:00 2001
From: Abigail <abigail@abigail.be>
Date: Fri, 29 Oct 2021 17:13:44 +0200
Subject: Check for even numbers.

In week 136, part 1, if one or both numbers are odd, the pair
cannot be two-friendly.
---
 challenge-136/abigail/awk/ch-1.gawk   |  4 ++++
 challenge-136/abigail/bash/ch-1.sh    |  6 +++++-
 challenge-136/abigail/bc/ch-1.bc      |  8 ++++++--
 challenge-136/abigail/c/ch-1.c        |  4 ++++
 challenge-136/abigail/go/ch-1.go      |  4 ++++
 challenge-136/abigail/java/ch-1.java  |  5 +++++
 challenge-136/abigail/lua/ch-1.lua    |  9 ++++++++-
 challenge-136/abigail/node/ch-1.js    |  4 ++++
 challenge-136/abigail/pascal/ch-1.p   | 12 ++++++++----
 challenge-136/abigail/perl/ch-1.pl    |  4 +++-
 challenge-136/abigail/python/ch-1.py  | 13 +++++++++----
 challenge-136/abigail/r/ch-1.r        | 15 ++++++++++-----
 challenge-136/abigail/ruby/ch-1.rb    |  8 ++++++--
 challenge-136/abigail/scheme/ch-1.scm | 12 ++++++++++--
 challenge-136/abigail/tcl/ch-1.tcl    | 12 ++++++++----
 15 files changed, 94 insertions(+), 26 deletions(-)

diff --git a/challenge-136/abigail/awk/ch-1.gawk b/challenge-136/abigail/awk/ch-1.gawk
index 12f563a4ea..0e8eb7d22a 100644
--- a/challenge-136/abigail/awk/ch-1.gawk
+++ b/challenge-136/abigail/awk/ch-1.gawk
@@ -37,6 +37,10 @@ function is_power_of_2 (number) {
     return is_power_of_n(number, 2)
 }
                  
+$1 % 2 || $2 % 2 {
+    print 0
+    next
+}
 
 {
     r = gcd($1, $2)
diff --git a/challenge-136/abigail/bash/ch-1.sh b/challenge-136/abigail/bash/ch-1.sh
index 857e3b7f7e..e965cbd96a 100644
--- a/challenge-136/abigail/bash/ch-1.sh
+++ b/challenge-136/abigail/bash/ch-1.sh
@@ -45,7 +45,11 @@ set -f
 
 
 while read n m
-do   gcd $n $m
+do   if ((n % 2 == 1 || m % 2 == 1))
+     then echo 0
+          continue
+     fi
+     gcd $n $m
      is_power_of_2 $gcd
      if ((gcd > 1 && is_power_of_2 == 1))
      then echo 1
diff --git a/challenge-136/abigail/bc/ch-1.bc b/challenge-136/abigail/bc/ch-1.bc
index 9a0c347386..a32d801dd8 100644
--- a/challenge-136/abigail/bc/ch-1.bc
+++ b/challenge-136/abigail/bc/ch-1.bc
@@ -28,8 +28,12 @@ define q (n) {
 while (1) {
     n = read (); if (n == 0) {break}
     m = read (); if (m == 0) {break}
-    r = g (n, m)
-    r > 1 && q (r)
+    if (n % 2 == 1 || m % 2 == 1) {
+        0
+    } else {
+        r = g (n, m)
+        r > 1 && q (r)
+    }
 }
 
 quit
diff --git a/challenge-136/abigail/c/ch-1.c b/challenge-136/abigail/c/ch-1.c
index d6fcc4d898..3c169dd635 100644
--- a/challenge-136/abigail/c/ch-1.c
+++ b/challenge-136/abigail/c/ch-1.c
@@ -45,6 +45,10 @@ int main (void) {
     long long n, m;
 
     while (scanf ("%lld %lld", &n, &m) == 2) {
+        if (n % 2 || m % 2) {
+            printf ("0\n");
+            continue;
+        }
         long long r = gcd (n, m);
         printf ("%d\n", r > 1 && is_power_of_2 (r) ? 1 : 0);
     }
diff --git a/challenge-136/abigail/go/ch-1.go b/challenge-136/abigail/go/ch-1.go
index 6c9e59ab1b..18e85a5dba 100644
--- a/challenge-136/abigail/go/ch-1.go
+++ b/challenge-136/abigail/go/ch-1.go
@@ -46,6 +46,10 @@ func main () {
         if c != 2 || err != nil {
             break;
         }
+        if n % 2 == 1 || m % 2 == 1 {
+            fmt . Print ("0\n")
+            continue
+        }
         if r := gcd (m, n); r > 1 && is_power_of_2 (r) {
             fmt . Print ("1\n")
         } else {
diff --git a/challenge-136/abigail/java/ch-1.java b/challenge-136/abigail/java/ch-1.java
index 4fbc1db180..639ef643ca 100644
--- a/challenge-136/abigail/java/ch-1.java
+++ b/challenge-136/abigail/java/ch-1.java
@@ -46,6 +46,11 @@ public class ch1 {
         while (scanner . hasNextInt ()) {
             int n = scanner . nextInt ();
             int m = scanner . nextInt ();
+            
+            if (n % 2 == 1 || m % 2 == 1) {
+                System . out . println ("0");
+                continue;
+            }
 
             int r = gcd (n, m);
 
diff --git a/challenge-136/abigail/lua/ch-1.lua b/challenge-136/abigail/lua/ch-1.lua
index 44ea00f251..369ee72246 100644
--- a/challenge-136/abigail/lua/ch-1.lua
+++ b/challenge-136/abigail/lua/ch-1.lua
@@ -31,10 +31,17 @@ end
 
 for line in io . lines () do
     local _, _, n, m = line : find ("([0-9]+)%s+([0-9]+)")
-    local r = gcd (tonumber (n), tonumber (m))
+    n = tonumber (n)
+    m = tonumber (m)
+    if n % 2 == 1 or m % 2 == 1 then
+        print (0)
+        goto continue
+    end
+    local r = gcd (n, m)
     if r > 1 and is_power_of_2 (r) then
         print (1)
     else
         print (0)
     end
+    ::continue::
 end
diff --git a/challenge-136/abigail/node/ch-1.js b/challenge-136/abigail/node/ch-1.js
index af49fa3977..4398a98d5a 100644
--- a/challenge-136/abigail/node/ch-1.js
+++ b/challenge-136/abigail/node/ch-1.js
@@ -33,6 +33,10 @@ function is_power_of_2 (number) {
 . createInterface ({input: process . stdin})   
 . on              ('line', line => {
     let [m, n] = line . trim () . split (' ') . map (x => +x)
+    if (n % 2 == 1 || m % 2 == 1) {
+        console . log (0)
+        return
+    }
     let  r     = gcd (m, n)
     if (r > 1 && is_power_of_2 (r)) {
         console . log (1)
diff --git a/challenge-136/abigail/pascal/ch-1.p b/challenge-136/abigail/pascal/ch-1.p
index 391a4fe69f..08004bf17b 100644
--- a/challenge-136/abigail/pascal/ch-1.p
+++ b/challenge-136/abigail/pascal/ch-1.p
@@ -55,10 +55,14 @@ var
 begin
     while (not eof) do begin
         readln (m, n);
-        r := gcd (m, n);
-        if (r > 1) and is_power_of_2 (r) then
-            writeln (1)
-        else
+        if (n mod 2 = 1) or (m mod 2 = 1) then
             writeln (0)
+        else begin
+            r := gcd (m, n);
+            if (r > 1) and is_power_of_2 (r) then
+                writeln (1)
+            else
+                writeln (0)
+        end
     end
 end.
diff --git a/challenge-136/abigail/perl/ch-1.pl b/challenge-136/abigail/perl/ch-1.pl
index ac0b598577..0c060f0299 100644
--- a/challenge-136/abigail/perl/ch-1.pl
+++ b/challenge-136/abigail/perl/ch-1.pl
@@ -59,6 +59,8 @@ sub is_power_of_2 ($number) {
 # Main program
 #
 while (<>) {
-    my  $r = gcd split;
+    my ($n, $m) = split;
+    say (0), next if ($n % 2) || ($m % 2);
+    my  $r = gcd $n, $m;
     say $r > 1 && is_power_of_2 ($r) ? 1 : 0
 }
diff --git a/challenge-136/abigail/python/ch-1.py b/challenge-136/abigail/python/ch-1.py
index 0c27429811..231e541d93 100644
--- a/challenge-136/abigail/python/ch-1.py
+++ b/challenge-136/abigail/python/ch-1.py
@@ -25,8 +25,13 @@ def is_power_of_2 (number):
 
 for line in fileinput . input ():
     m, n = line . strip () . split (' ')
-    r = math . gcd (int (m), int (n))
-    if r > 1 and is_power_of_2 (r):
-        print (1)
-    else:
+    m = int (m)
+    n = int (n)
+    if m % 2 or n % 2:
         print (0)
+    else:
+        r = math . gcd (m, n)
+        if r > 1 and is_power_of_2 (r):
+            print (1)
+        else:
+            print (0)
diff --git a/challenge-136/abigail/r/ch-1.r b/challenge-136/abigail/r/ch-1.r
index 1231a1c2a8..851c753f4e 100644
--- a/challenge-136/abigail/r/ch-1.r
+++ b/challenge-136/abigail/r/ch-1.r
@@ -42,12 +42,17 @@ repeat {
     m <- as.numeric (parts [[1]] [[1]])
     n <- as.numeric (parts [[1]] [[2]])
 
-    r <- gcd (n, m)
-
-    if (r > 1 & is_power_of_2 (r)) {
-        cat ("1\n")
+    if (n %% 2 == 1 | m %% 2 == 1) {
+        cat ("0\n")
     }
     else {
-        cat ("0\n")
+        r <- gcd (n, m)
+
+        if (r > 1 & is_power_of_2 (r)) {
+            cat ("1\n")
+        }
+        else {
+            cat ("0\n")
+        }
     }
 }
diff --git a/challenge-136/abigail/ruby/ch-1.rb b/challenge-136/abigail/ruby/ch-1.rb
index aa050a843e..37e005400c 100644
--- a/challenge-136/abigail/ruby/ch-1.rb
+++ b/challenge-136/abigail/ruby/ch-1.rb
@@ -22,6 +22,10 @@ end
 ARGF . each_line do
     | line |
     m, n = line . split . map {|x| x . to_i}
-    r = m . gcd (n)
-    puts (r > 1 && is_power_of_2(r) ? 1 : 0)
+    if n % 2 == 1 || m % 2 == 1 then
+        puts (0)
+    else
+        r = m . gcd (n)
+        puts (r > 1 && is_power_of_2(r) ? 1 : 0)
+    end
 end
diff --git a/challenge-136/abigail/scheme/ch-1.scm b/challenge-136/abigail/scheme/ch-1.scm
index d537b754e0..aa6b75705a 100644
--- a/challenge-136/abigail/scheme/ch-1.scm
+++ b/challenge-136/abigail/scheme/ch-1.scm
@@ -44,8 +44,16 @@
     (define r)
     (if (not (eof-object? m))
         (begin
-            (set! r (gcd m n))
-            (display (if (and (> r 1) (is-power-of-2 r)) 1 0))
+            (display (cond ((= (modulo n 2) 1) 0)
+                           ((= (modulo m 2) 1) 0)
+                           (else
+                               (begin
+                                   (set! r (gcd m n))
+                                   (if (and (> r 1) (is-power-of-2 r)) 1 0)
+                               )
+                           )
+                      )
+            )
             (newline)
             (main)
         )
diff --git a/challenge-136/abigail/tcl/ch-1.tcl b/challenge-136/abigail/tcl/ch-1.tcl
index 39210c7e16..af5a72a3ea 100644
--- a/challenge-136/abigail/tcl/ch-1.tcl
+++ b/challenge-136/abigail/tcl/ch-1.tcl
@@ -47,10 +47,14 @@ proc is_power_of_2 {number} {
 
 while {[gets stdin line] >= 0} {
     lassign [split $line " "] m n
-    set r [gcd $m $n]
-    if {$r > 1 && [is_power_of_2 $r]} {
-        puts 1
-    } else {
+    if {[expr $m % 2] == 1 || [expr $n % 2] == 1} {
         puts 0
+    } else {
+        set r [gcd $m $n]
+        if {$r > 1 && [is_power_of_2 $r]} {
+            puts 1
+        } else {
+            puts 0
+        }
     }
 }
-- 
cgit 


From b90fe902e06fa33e66b75c3408a988812f93c3ed Mon Sep 17 00:00:00 2001
From: Luca Ferrari <fluca1978@gmail.com>
Date: Fri, 29 Oct 2021 18:36:57 +0200
Subject: Task solved as PostgreSQL functions

---
 challenge-136/luca-ferrari/postgresql/ch-1.sql | 24 +++++++++++++++++++
 challenge-136/luca-ferrari/postgresql/ch-2.sql | 33 ++++++++++++++++++++++++++
 2 files changed, 57 insertions(+)
 create mode 100644 challenge-136/luca-ferrari/postgresql/ch-1.sql
 create mode 100644 challenge-136/luca-ferrari/postgresql/ch-2.sql

diff --git a/challenge-136/luca-ferrari/postgresql/ch-1.sql b/challenge-136/luca-ferrari/postgresql/ch-1.sql
new file mode 100644
index 0000000000..ed1f0c71a0
--- /dev/null
+++ b/challenge-136/luca-ferrari/postgresql/ch-1.sql
@@ -0,0 +1,24 @@
+/*
+testdb=> SELECT FRIENDLY( 26, 39 );
+friendly
+----------
+0
+(1 row)
+
+testdb=> SELECT FRIENDLY( 26, 52 );
+friendly
+----------
+1
+(1 row)
+
+*/
+CREATE OR REPLACE FUNCTION friendly( m int, n int )
+RETURNS int
+AS $CODE$
+   SELECT
+        CASE gcd( m, n ) % 2
+             WHEN 0  THEN 1
+             ELSE 0
+        END;
+$CODE$
+LANGUAGE SQL;
diff --git a/challenge-136/luca-ferrari/postgresql/ch-2.sql b/challenge-136/luca-ferrari/postgresql/ch-2.sql
new file mode 100644
index 0000000000..e1f6439ec0
--- /dev/null
+++ b/challenge-136/luca-ferrari/postgresql/ch-2.sql
@@ -0,0 +1,33 @@
+CREATE OR REPLACE FUNCTION fibonacci_sum( l int DEFAULT 16 )
+RETURNS bigint
+AS $CODE$
+
+WITH RECURSIVE
+fibonacci( n, p ) AS
+(
+        SELECT 1, 1
+        UNION
+        SELECT p + n, n
+        FROM fibonacci
+        WHERE n < l
+)
+, permutations AS
+(
+        SELECT n::text AS current_value, n as total_sum
+        FROM fibonacci
+        UNION
+        SELECT current_value || ',' || n, total_sum + n
+        FROM permutations, fibonacci
+        WHERE
+                position( n::text in  current_value ) = 0
+       AND n > ALL( string_to_array( current_value, ',' )::int[] )
+
+
+)
+SELECT count(*)
+FROM permutations
+WHERE total_sum = l
+;
+
+$CODE$
+LANGUAGE SQL;
-- 
cgit 


From 70cd62f9a8258b22cd2d385fa65c265e6f6423f1 Mon Sep 17 00:00:00 2001
From: Luca Ferrari <fluca1978@gmail.com>
Date: Fri, 29 Oct 2021 18:57:00 +0200
Subject: Blog references to the PostgreSQL solutions

---
 challenge-136/luca-ferrari/blog-3.txt | 1 +
 challenge-136/luca-ferrari/blog-4.txt | 1 +
 2 files changed, 2 insertions(+)
 create mode 100644 challenge-136/luca-ferrari/blog-3.txt
 create mode 100644 challenge-136/luca-ferrari/blog-4.txt

diff --git a/challenge-136/luca-ferrari/blog-3.txt b/challenge-136/luca-ferrari/blog-3.txt
new file mode 100644
index 0000000000..fd8dbeb710
--- /dev/null
+++ b/challenge-136/luca-ferrari/blog-3.txt
@@ -0,0 +1 @@
+https://fluca1978.github.io/2021/10/29/PerlWeeklyChallenge136PostgreSQL.html#task1
diff --git a/challenge-136/luca-ferrari/blog-4.txt b/challenge-136/luca-ferrari/blog-4.txt
new file mode 100644
index 0000000000..f9b68dd456
--- /dev/null
+++ b/challenge-136/luca-ferrari/blog-4.txt
@@ -0,0 +1 @@
+https://fluca1978.github.io/2021/10/29/PerlWeeklyChallenge136PostgreSQL.html#task2
-- 
cgit 


From 0eda758bb14b0a50fcbced7b0c19fb6cfb291761 Mon Sep 17 00:00:00 2001
From: "E. Choroba" <choroba@matfyz.cz>
Date: Fri, 29 Oct 2021 20:41:21 +0200
Subject: Add DP solution to 136/2

---
 challenge-136/e-choroba/perl/ch-2.pl | 30 ++++++++++++++++++++++++++++--
 1 file changed, 28 insertions(+), 2 deletions(-)

diff --git a/challenge-136/e-choroba/perl/ch-2.pl b/challenge-136/e-choroba/perl/ch-2.pl
index 475a906652..40a1f711e7 100755
--- a/challenge-136/e-choroba/perl/ch-2.pl
+++ b/challenge-136/e-choroba/perl/ch-2.pl
@@ -5,7 +5,7 @@ use strict;
 use List::Util qw{ sum };
 
 my @F = (1, 2);
-sub fibonacci_sequence {
+sub fibonacci_sequence_indicator {
     my ($n) = @_;
     my $count = 0;
     my $indicator = 1;
@@ -21,8 +21,30 @@ sub fibonacci_sequence {
     return $count
 }
 
+my %fs = (1 => [[1]], 2 => [[2]]);
+sub fs_dynamic {
+    my ($n) = @_;
+    return @{ $fs{$n} } if exists $fs{$n};
+
+    push @F, $F[-2] + $F[-1] while $F[-1] < $n;
+    my @result;
+    for my $f (grep $_ <= $n, @F) {
+        no warnings 'recursion';
+        my @without = grep { ! grep $_ == $f, @$_ } fs_dynamic($n - $f);
+        next if @without && $f < $without[0][0];
+
+        push @result, map [$f, @$_], @without;
+        push @result, [$f] if $n == $f;
+    }
+    return @{ $fs{$n} = \@result }
+}
+
+sub fibonacci_sequence {
+    scalar fs_dynamic(@_)
+}
+
 use Test2::V0;
-plan 52;
+plan 118;
 
 is fibonacci_sequence(16), 4, 'Example 1';
 is fibonacci_sequence(9), 2, 'Example 2';
@@ -47,6 +69,7 @@ is fibonacci_sequence(29), 5, 'Check 29';
 is fibonacci_sequence(30), 3, 'Check 30';
 is fibonacci_sequence(31), 3, 'Check 31';
 is fibonacci_sequence(32), 4, 'Check 32';
+
 is fibonacci_sequence(33), 1, 'Check 33';
 is fibonacci_sequence(34), 4, 'Check 34';
 is fibonacci_sequence(35), 4, 'Check 35';
@@ -80,3 +103,6 @@ is fibonacci_sequence(62), 3, 'Check 62';
 is fibonacci_sequence(63), 8, 'Check 63';
 is fibonacci_sequence(64), 5, 'Check 64';
 is fibonacci_sequence(65), 5, 'Check 65';
+
+is fibonacci_sequence($_), fibonacci_sequence_indicator($_), "same $_"
+    for 1 .. 65, 1234;
-- 
cgit 


From 14a1b81924ec23b65d4d1da7ca6f742b8494ebed Mon Sep 17 00:00:00 2001
From: Abigail <abigail@abigail.be>
Date: Fri, 29 Oct 2021 20:46:03 +0200
Subject: Use longint instead integer.

Integers can be as small as 16bits; longints are 32bits.
---
 challenge-136/abigail/pascal/ch-1.p | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/challenge-136/abigail/pascal/ch-1.p b/challenge-136/abigail/pascal/ch-1.p
index 08004bf17b..7c3e122dee 100644
--- a/challenge-136/abigail/pascal/ch-1.p
+++ b/challenge-136/abigail/pascal/ch-1.p
@@ -12,7 +12,7 @@ Program XXX;
 (* Find the GCD, using Stein's algorithm                   *)   
 (*    (https://en.wikipedia.org/wiki/Binary_GCD_algorithm) *)
 (*                                                         *)
-function gcd (u, v: integer): integer;
+function gcd (u, v: longint): longint;
     var
         u_odd, v_odd: boolean;
 
@@ -34,7 +34,7 @@ function gcd (u, v: integer): integer;
 (* Return true if number is a power of n, that is, number == n ^ p *)
 (* for some non-negative integer p. Return false otherwise.        *)
 (*                                                                 *)
-function is_power_of_n (number, n: integer): boolean;
+function is_power_of_n (number, n: longint): boolean;
     begin
              if number < 1        then is_power_of_n := false
         else if number = 1        then is_power_of_n := true
@@ -42,7 +42,7 @@ function is_power_of_n (number, n: integer): boolean;
         else is_power_of_n := is_power_of_n (number div n, n);
     end;
 
-function is_power_of_2 (number: integer): boolean;
+function is_power_of_2 (number: longint): boolean;
     begin
         is_power_of_2 := is_power_of_n (number, 2);
     end;
@@ -50,7 +50,7 @@ function is_power_of_2 (number: integer): boolean;
 
 
 var
-    m, n, r: integer;
+    m, n, r: longint;
 
 begin
     while (not eof) do begin
-- 
cgit 


From 8d617f0b82a667a72a48233d2bde1bdd6bc1144d Mon Sep 17 00:00:00 2001
From: PerlMonk-Athanasius <PerlMonk.Athanasius@gmail.com>
Date: Sat, 30 Oct 2021 22:05:06 +1000
Subject: Perl & Raku solutions to Tasks 1 & 2 of the Perl Weekly Challenge
 #136

---
 challenge-136/athanasius/perl/ch-1.pl   | 157 +++++++++++++++++++++++
 challenge-136/athanasius/perl/ch-2.pl   | 213 ++++++++++++++++++++++++++++++++
 challenge-136/athanasius/raku/ch-1.raku | 122 ++++++++++++++++++
 challenge-136/athanasius/raku/ch-2.raku | 176 ++++++++++++++++++++++++++
 4 files changed, 668 insertions(+)
 create mode 100644 challenge-136/athanasius/perl/ch-1.pl
 create mode 100644 challenge-136/athanasius/perl/ch-2.pl
 create mode 100644 challenge-136/athanasius/raku/ch-1.raku
 create mode 100644 challenge-136/athanasius/raku/ch-2.raku

diff --git a/challenge-136/athanasius/perl/ch-1.pl b/challenge-136/athanasius/perl/ch-1.pl
new file mode 100644
index 0000000000..f76757eb3f
--- /dev/null
+++ b/challenge-136/athanasius/perl/ch-1.pl
@@ -0,0 +1,157 @@
+#!perl
+
+###############################################################################
+=comment
+
+Perl Weekly Challenge 136
+=========================
+
+TASK #1
+-------
+*Two Friendly*
+
+Submitted by: Mohammad S Anwar
+
+You are given 2 positive numbers, $m and $n.
+
+Write a script to find out if the given two numbers are Two Friendly.
+
+    Two positive numbers, m and n are two friendly when gcd(m, n) = 2 ^ p where
+    p > 0. The greatest common divisor (gcd) of a set of numbers is the largest
+    positive number that divides all the numbers in the set without remainder.
+
+Example 1
+
+    Input: $m = 8, $n = 24
+    Output: 1
+
+    Reason: gcd(8,24) = 8 => 2 ^ 3
+
+Example 2
+
+    Input: $m = 26, $n = 39
+    Output: 0
+
+    Reason: gcd(26,39) = 13
+
+Example 3
+
+    Input: $m = 4, $n = 10
+    Output: 1
+
+    Reason: gcd(4,10) = 2 => 2 ^ 1
+
+=cut
+###############################################################################
+
+#--------------------------------------#
+# Copyright © 2021 PerlMonk Athanasius #
+#--------------------------------------#
+
+#==============================================================================
+=comment
+
+Interface
+---------
+Include the flag "--verbose" (or just "-v") on the command line to display an
+explanation of the output.
+
+Implementation
+--------------
+Calculation of the greatest common divisor is delegated to the gcd() subroutine
+in the ntheory (aka Math::Prime::Util) module.
+
+=cut
+#==============================================================================
+
+use strict;
+use warnings;
+use Const::Fast;
+use Getopt::Long;
+use ntheory        qw( gcd );
+use Regexp::Common qw( number );
+
+const my $USAGE =>
+"Usage:
+  perl $0 [--verbose|-v] <m> <n>
+
+    --verbose    Explain the output?
+    <m>          An integer > 0
+    <n>          An integer > 0\n";
+
+#------------------------------------------------------------------------------
+BEGIN
+#------------------------------------------------------------------------------
+{
+    $| = 1;
+    print "\nChallenge 136, Task #1: Two Friendly (Perl)\n\n";
+}
+
+#==============================================================================
+MAIN:
+#==============================================================================
+{
+    my ($verbose, $m, $n) = parse_command_line();
+
+    print "Input:  \$m = $m, \$n = $n\n";
+
+    my $friendly = 0;
+    my $reason   = 'not a power of 2';
+    my $gcd      = gcd( $m, $n );
+
+    if ($gcd == 1)
+    {
+        $reason = '2 ^ 0';
+    }
+    else
+    {
+        my $log2 = int( (log( $gcd ) / log( 2 )) + 0.5 );
+
+        if ($gcd == 2 ** $log2)
+        {
+            $friendly = 1;
+            $reason   = "2 ^ $log2";
+        }
+    }
+
+    printf "Output: %d\n", $friendly ? 1 : 0;
+
+    print "\nReason: gcd($m, $n) = $gcd which is $reason\n" if $verbose;
+}
+
+#------------------------------------------------------------------------------
+sub parse_command_line
+#------------------------------------------------------------------------------
+{
+    my $verbose = 0;
+
+    GetOptions( verbose => \$verbose )
+               or error( 'Invalid command line flag' );
+
+    my $args = scalar @ARGV;
+       $args == 2
+               or error( "Expected 2 command line arguments, found $args" );
+
+    my ($m, $n) = @ARGV;
+
+    for ($m, $n)
+    {
+        / ^ $RE{num}{int} $ /x
+               or error( qq["$_" is not a valid integer] );
+
+        $_ > 0 or error( qq["$_" is not greater than zero] );
+    }
+
+    return ($verbose, $m, $n);
+}
+
+#------------------------------------------------------------------------------
+sub error
+#------------------------------------------------------------------------------
+{
+    my ($message) = @_;
+
+    die "ERROR: $message\n$USAGE";
+}
+
+###############################################################################
diff --git a/challenge-136/athanasius/perl/ch-2.pl b/challenge-136/athanasius/perl/ch-2.pl
new file mode 100644
index 0000000000..ed97d62121
--- /dev/null
+++ b/challenge-136/athanasius/perl/ch-2.pl
@@ -0,0 +1,213 @@
+#!perl
+
+###############################################################################
+=comment
+
+Perl Weekly Challenge 136
+=========================
+
+TASK #2
+-------
+*Fibonacci Sequence*
+
+Submitted by: Mohammad S Anwar
+
+You are given a positive number $n.
+
+Write a script to find how many different sequences you can create using
+Fibonacci numbers where the sum of unique numbers in each sequence are the same
+as the given number.
+
+    Fibonacci Numbers: 1,2,3,5,8,13,21,34,55,89, …
+
+Example 1
+
+  Input:  $n = 16
+  Output: 4
+
+  Reason: There are 4 possible sequences that can be created using Fibonacci
+  numbers i.e. (3 + 13), (1 + 2 + 13), (3 + 5 + 8) and (1 + 2 + 5 + 8).
+
+Example 2
+
+  Input:  $n = 9
+  Output: 2
+
+  Reason: There are 2 possible sequences that can be created using Fibonacci
+  numbers i.e. (1 + 3 + 5) and (1 + 8).
+
+Example 3
+
+  Input:  $n = 15
+  Output: 2
+
+  Reason: There are 2 possible sequences that can be created using Fibonacci
+  numbers i.e. (2 + 5 + 8) and (2 + 13).
+
+=cut
+###############################################################################
+
+#--------------------------------------#
+# Copyright © 2021 PerlMonk Athanasius #
+#--------------------------------------#
+
+#==============================================================================
+=comment
+
+Interface
+---------
+Include the flag "--verbose" (or just "-v") on the command line to display an
+explanation of the output.
+
+Algorithm
+---------
+1. Find the set F of Fibonacci numbers less than or equal to $n
+2. Calculate the power set P(F) of all subsets of F
+3. For each subset S in P(F), sum the elements of S and add S to the solution
+   set iff the sum equals $n
+
+Note: This algorithm works well for smaller values of $n, but will not scale
+well for larger values.
+
+Implementation
+--------------
+Calculation of the power set is delegated to the subsets() subroutine of module
+Algorithm::Combinatorics. See:
+    https://rosettacode.org/wiki/Power_set#Module:_Algorithm::Combinatorics
+
+=cut
+#==============================================================================
+
+use strict;
+use warnings;
+use Algorithm::Combinatorics qw( subsets );
+use Const::Fast;
+use Getopt::Long;
+use Regexp::Common           qw( number );
+
+const my $USAGE =>
+"Usage:
+  perl $0 [--verbose|-v] <n>
+
+    --verbose    Explain the output?
+    <n>          An integer > 0\n";
+
+#------------------------------------------------------------------------------
+BEGIN
+#------------------------------------------------------------------------------
+{
+    $| = 1;
+    print "\nChallenge 136, Task #2: Fibonacci Sequence (Perl)\n\n";
+}
+
+#==============================================================================
+MAIN:
+#==============================================================================
+{
+    my ($verbose, $n) = parse_command_line();
+
+    print "Input:  \$n = $n\n";
+
+    my $seqs  = find_fib_seqs( $n );
+    my $count = scalar @$seqs;
+
+    print "Output: $count\n";
+
+    if ($verbose)
+    {
+        if    ($count == 0)
+        {
+            print  "\nReason: There are no possible sequences summing to $n" .
+                   "\n\tthat can be created using unique Fibonacci numbers\n";
+        }
+        elsif ($count == 1)
+        {
+            printf "\nReason: There is one possible sequence summing to %d"  .
+                   "\n\tthat can be created using unique Fibonacci numbers:" .
+                   "\n\t(%s)\n", $n, join ' + ', @{ $seqs->[ 0 ] };
+        }
+        else
+        {
+            printf "\nReason: There are %d possible sequences summing to %d" .
+                   "\n\tthat can be created using unique Fibonacci numbers:\n",
+                    $count, $n;
+
+            printf "\t(%s)\n", join ' + ', @$_ for @$seqs;
+        }
+    }
+}
+
+#------------------------------------------------------------------------------
+sub find_fib_seqs
+#------------------------------------------------------------------------------
+{
+    my ($n)   = @_;
+    my  @seqs;
+    my  $fibs = get_fib_nums( $n );
+    my  $iter = subsets( $fibs );
+
+    while (my $p = $iter->next)
+    {
+        my $sum  = 0;
+           $sum += $_ for @$p;
+
+        push @seqs, $p if $sum == $n;
+    }
+
+    return \@seqs;
+}
+
+#------------------------------------------------------------------------------
+sub get_fib_nums
+#------------------------------------------------------------------------------
+{
+    my ($n)     = @_;
+    my  @fibs   = (1);
+    my ($x, $y) = (1, 1);
+
+    while ($fibs[ -1 ] < $n)
+    {
+        my $z = $x + $y;
+        push @fibs, $z;
+        $x = $y;
+        $y = $z;
+    }
+
+    pop @fibs if $fibs[ -1 ] > $n;
+
+    return \@fibs;
+}
+
+#------------------------------------------------------------------------------
+sub parse_command_line
+#------------------------------------------------------------------------------
+{
+    my $verbose = 0;
+
+    GetOptions( verbose => \$verbose )
+              or error( 'Invalid command line flag' );
+
+    my $args = scalar @ARGV;
+       $args == 1
+              or error( "Expected 1 command line argument, found $args" );
+
+    my $n = $ARGV[ 0 ];
+
+       $n =~ / ^ $RE{num}{int} $ /x
+              or error( qq["$n" is not a valid integer] );
+
+       $n > 0 or error( qq["$n" is not greater than zero] );
+
+    return ($verbose, $n);
+}
+
+#------------------------------------------------------------------------------
+sub error
+#------------------------------------------------------------------------------
+{
+    my ($message) = @_;
+
+    die "ERROR: $message\n$USAGE";
+}
+
+###############################################################################
diff --git a/challenge-136/athanasius/raku/ch-1.raku b/challenge-136/athanasius/raku/ch-1.raku
new file mode 100644
index 0000000000..8aed05ef23
--- /dev/null
+++ b/challenge-136/athanasius/raku/ch-1.raku
@@ -0,0 +1,122 @@
+use v6d;
+
+###############################################################################
+=begin comment
+
+Perl Weekly Challenge 136
+=========================
+
+TASK #1
+-------
+*Two Friendly*
+
+Submitted by: Mohammad S Anwar
+
+You are given 2 positive numbers, $m and $n.
+
+Write a script to find out if the given two numbers are Two Friendly.
+
+    Two positive numbers, m and n are two friendly when gcd(m, n) = 2 ^ p where
+    p > 0. The greatest common divisor (gcd) of a set of numbers is the largest
+    positive number that divides all the numbers in the set without remainder.
+
+Example 1
+
+    Input: $m = 8, $n = 24
+    Output: 1
+
+    Reason: gcd(8,24) = 8 => 2 ^ 3
+
+Example 2
+
+    Input: $m = 26, $n = 39
+    Output: 0
+
+    Reason: gcd(26,39) = 13
+
+Example 3
+
+    Input: $m = 4, $n = 10
+    Output: 1
+
+    Reason: gcd(4,10) = 2 => 2 ^ 1
+
+=end comment
+###############################################################################
+
+#--------------------------------------#
+# Copyright © 2021 PerlMonk Athanasius #
+#--------------------------------------#
+
+#==============================================================================
+=begin comment
+
+Interface
+---------
+Include the flag "--verbose" on the command line to display an explanation of
+the output.
+
+Implementation
+--------------
+Calculation of the greatest common divisor is performed by Raku's inbuilt infix
+operator "gcd".
+
+=end comment
+#==============================================================================
+
+subset Positive of Int where * > 0;
+
+#------------------------------------------------------------------------------
+BEGIN
+#------------------------------------------------------------------------------
+{
+    "\nChallenge 136, Task #1: Two Friendly (Raku)\n".put;
+}
+
+#==============================================================================
+sub MAIN
+(
+    Positive:D $m,                          #= An integer > 0
+    Positive:D $n,                          #= An integer > 0
+    Bool:D    :$verbose = False             #= Explain the output?
+)
+#==============================================================================
+{
+    "Input:  \$m = $m, \$n = $n".put;
+
+    my Bool     $friendly = False;
+    my Str      $reason   = 'not a power of 2';
+    my Positive $gcd      = $m gcd $n;
+
+    if $gcd == 1
+    {
+        $reason = '2 ^ 0';
+    }
+    else
+    {
+        my Int $log2 = ($gcd.log2 + 0.5).Int;
+
+        if $gcd == 2 ** $log2
+        {
+            $friendly = True;
+            $reason   = "2 ^ $log2";
+        }
+    }
+
+    "Output: %d\n".printf: $friendly ?? 1 !! 0;
+
+    "\nReason: gcd($m, $n) = $gcd which is $reason".put if $verbose;
+}
+
+#------------------------------------------------------------------------------
+sub USAGE()
+#------------------------------------------------------------------------------
+{
+    my Str $usage = $*USAGE;
+
+    $usage ~~ s/ ($*PROGRAM-NAME) /raku $0/;
+
+    $usage.put;
+}
+
+##############################################################################
diff --git a/challenge-136/athanasius/raku/ch-2.raku b/challenge-136/athanasius/raku/ch-2.raku
new file mode 100644
index 0000000000..653d86afe8
--- /dev/null
+++ b/challenge-136/athanasius/raku/ch-2.raku
@@ -0,0 +1,176 @@
+use v6d;
+
+###############################################################################
+=begin comment
+
+Perl Weekly Challenge 136
+=========================
+
+TASK #2
+-------
+*Fibonacci Sequence*
+
+Submitted by: Mohammad S Anwar
+
+You are given a positive number $n.
+
+Write a script to find how many different sequences you can create using
+Fibonacci numbers where the sum of unique numbers in each sequence are the same
+as the given number.
+
+    Fibonacci Numbers: 1,2,3,5,8,13,21,34,55,89, …
+
+Example 1
+
+  Input:  $n = 16
+  Output: 4
+
+  Reason: There are 4 possible sequences that can be created using Fibonacci
+  numbers i.e. (3 + 13), (1 + 2 + 13), (3 + 5 + 8) and (1 + 2 + 5 + 8).
+
+Example 2
+
+  Input:  $n = 9
+  Output: 2
+
+  Reason: There are 2 possible sequences that can be created using Fibonacci
+  numbers i.e. (1 + 3 + 5) and (1 + 8).
+
+Example 3
+
+  Input:  $n = 15
+  Output: 2
+
+  Reason: There are 2 possible sequences that can be created using Fibonacci
+  numbers i.e. (2 + 5 + 8) and (2 + 13).
+
+=end comment
+###############################################################################
+
+#--------------------------------------#
+# Copyright © 2021 PerlMonk Athanasius #
+#--------------------------------------#
+
+#==============================================================================
+=begin comment
+
+Interface
+---------
+Include the flag "--verbose" on the command line to display an explanation of
+the output.
+
+Algorithm
+---------
+1. Find the set F of Fibonacci numbers less than or equal to $n
+2. Calculate the power set P(F) of all subsets of F
+3. For each subset S in P(F), sum the elements of S and add S to the solution
+   set iff the sum equals $n
+
+Note: This algorithm works well for smaller values of $n, but will not scale
+well for larger values.
+
+Implementation
+--------------
+Calculation of the power set is performed by Raku's inbuilt combinations()
+method.
+
+=end comment
+#==============================================================================
+
+subset Pos of Int where * > 0;
+
+#------------------------------------------------------------------------------
+BEGIN
+#------------------------------------------------------------------------------
+{
+    "\nChallenge 136, Task #2: Fibonacci Sequence (Raku)\n".put;
+}
+
+#==============================================================================
+sub MAIN
+(
+    Pos:D   $n,                           #= An integer > 0
+    Bool:D :$verbose = False              #= Explain the output?
+)
+#==============================================================================
+{
+    "Input:  \$n = $n".put;
+
+    my Array[Pos] @seqs  = find-fib-seqs( $n );
+    my UInt       $count = @seqs.elems;
+
+    "Output: $count".put;
+
+    if $verbose
+    {
+        if    $count == 0
+        {
+            ("\nReason: There are no possible sequences summing to $n" ~
+             "\n\tthat can be created using unique Fibonacci numbers").put;
+        }
+        elsif $count == 1
+        {
+            ("\nReason: There is one possible sequence summing to $n"  ~
+             "\n\tthat can be created using unique Fibonacci numbers:" ~
+             "\n\t(%s)\n").printf: @seqs[ 0 ].join: ' + ';
+        }
+        else
+        {
+            ("\nReason: There are $count possible sequences summing to $n" ~
+             "\n\tthat can be created using unique Fibonacci numbers:").put;
+
+             "\t(%s)\n".printf: $_.join: ' + ' for @seqs;
+        }
+    }
+}
+
+#------------------------------------------------------------------------------
+sub find-fib-seqs( Pos:D $n --> Array:D[Array:D[Pos:D]] )
+#------------------------------------------------------------------------------
+{
+    my Array[Pos] @seqs;
+    my Array[Pos] $fibs = get-fib-nums( $n );
+
+    for $fibs.combinations: 1 .. * -> List $c
+    {
+        my UInt $sum = [+] @$c;              # Sum using reduction metaoperator
+
+        @seqs.push: Array[Pos].new: @$c if $sum == $n;
+    }
+
+    return @seqs;
+}
+
+#------------------------------------------------------------------------------
+sub get-fib-nums( Pos:D $n --> Array:D[Pos:D] )
+#------------------------------------------------------------------------------
+{
+    my Pos  @fibs   =  1;
+    my Pos ($x, $y) = (1, 1);
+
+    while @fibs[ *-1 ] < $n
+    {
+        my Pos $z = $x + $y;
+
+        @fibs.push: $z;
+
+        $x = $y;
+        $y = $z;
+    }
+
+    @fibs.pop if @fibs[ *-1 ] > $n;
+
+    return @fibs;
+}
+
+#------------------------------------------------------------------------------
+sub USAGE()
+#------------------------------------------------------------------------------
+{
+    my Str $usage = $*USAGE;
+
+    $usage ~~ s/ ($*PROGRAM-NAME) /raku $0/;
+    $usage.put;
+}
+
+##############################################################################
-- 
cgit 


From 9890eb4d1023c0a56da3652c1c60128b5a84eee8 Mon Sep 17 00:00:00 2001
From: James Smith <js5@sanger.ac.uk>
Date: Sat, 30 Oct 2021 16:05:28 +0100
Subject: Create blog.txt

---
 challenge-134/james-smith/blog.txt | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 challenge-134/james-smith/blog.txt

diff --git a/challenge-134/james-smith/blog.txt b/challenge-134/james-smith/blog.txt
new file mode 100644
index 0000000000..515dacf030
--- /dev/null
+++ b/challenge-134/james-smith/blog.txt
@@ -0,0 +1 @@
+https://github.com/drbaggy/perlweeklychallenge-club/tree/master/challenge-134/james-smith
-- 
cgit 


From 9c34496daf88ee295dc4e14d8afb9569560d632e Mon Sep 17 00:00:00 2001
From: Matthew Neleigh <matthew.neleigh@gmail.com>
Date: Sat, 30 Oct 2021 12:24:36 -0400
Subject: 	new file:   challenge-136/mattneleigh/perl/ch-1.pl

---
 challenge-136/mattneleigh/perl/ch-1.pl | 84 ++++++++++++++++++++++++++++++++++
 1 file changed, 84 insertions(+)
 create mode 100755 challenge-136/mattneleigh/perl/ch-1.pl

diff --git a/challenge-136/mattneleigh/perl/ch-1.pl b/challenge-136/mattneleigh/perl/ch-1.pl
new file mode 100755
index 0000000000..31a755832a
--- /dev/null
+++ b/challenge-136/mattneleigh/perl/ch-1.pl
@@ -0,0 +1,84 @@
+#!/usr/bin/perl
+
+use strict;
+use warnings;
+use English;
+
+################################################################################
+# Begin main execution
+################################################################################
+
+my @pairs = (
+    [ 8, 24 ],
+    [ 26, 39 ],
+    [ 4, 10 ]
+);
+my $pair;
+
+foreach $pair (@pairs){
+    print("    Input: \$m = $pair->[0], \$n = $pair->[1]\n");
+    print("    Output: ", two_friendly(@{$pair}), "\n\n\n");
+}
+
+exit(0);
+################################################################################
+# End main execution; subroutines follow
+################################################################################
+
+
+
+################################################################################
+# Determine of two integers are Two Friendly (their Greatest Common Divisor is
+# a Power of Two)
+# Takes two arguments:
+# * An integer M
+# * An integer N
+# Returns:
+# * 1 if M and N are Two Friendly
+# * 0 if M and N are NOT Two Friendly
+################################################################################
+sub two_friendly{
+    my $m = int(shift());
+    my $n = int(shift());
+
+    my $power_two;
+
+    # Compute the power of two of the greatest
+    # common divisor
+    $power_two = log(gcd($m, $n)) / log(2);
+
+    # If $power_two looks like an integer
+    # (accounting for round-off error...) then
+    # the GCD of $m and $n was a power of two
+    if(abs($power_two - int($power_two)) < 0.0000000001){
+        return(1);
+    } else{
+        return(0);
+    }
+
+}
+
+
+
+################################################################################
+# Compute the Greatest Common Denominator (GCD) of two integers
+# Takes two arguments:
+# * An integer A
+# * An integer B
+# Returns:
+# * The GCD of A and B
+################################################################################
+sub gcd{
+    my $a = shift();
+    my $b = shift();
+
+    if($b){
+        return(gcd($b, $a % $b));
+    } else{
+        return($a);
+    }
+
+}
+
+
+
-- 
cgit 


From c0c3c19fee82da1d819b3c8a61a6c45e48449c75 Mon Sep 17 00:00:00 2001
From: dcw <d.white@imperial.ac.uk>
Date: Sat, 30 Oct 2021 21:57:43 +0100
Subject: imported my solutions to this week's challenges; two nice tasks

---
 challenge-136/duncan-c-white/README       |  75 +++++++++++-------
 challenge-136/duncan-c-white/perl/ch-1.pl |  74 ++++++++++++++++++
 challenge-136/duncan-c-white/perl/ch-2.pl | 124 ++++++++++++++++++++++++++++++
 3 files changed, 246 insertions(+), 27 deletions(-)
 create mode 100755 challenge-136/duncan-c-white/perl/ch-1.pl
 create mode 100755 challenge-136/duncan-c-white/perl/ch-2.pl

diff --git a/challenge-136/duncan-c-white/README b/challenge-136/duncan-c-white/README
index 9e73de07f7..c41627048b 100644
--- a/challenge-136/duncan-c-white/README
+++ b/challenge-136/duncan-c-white/README
@@ -1,56 +1,77 @@
-TASK #1 - Middle 3-digits
+TASK #1 - Two Friendly
 
-You are given an integer.
+You are given 2 positive numbers, $m and $n.
 
-Write a script find out the middle 3-digits of the given integer, if
-possible otherwise throw sensible error.
+Write a script to find out if the given two numbers are Two Friendly.
+
+Two positive numbers, m and n are two friendly when gcd(m, n) = 2 ^
+p where p > 0. The greatest common divisor (gcd) of a set of numbers
+is the largest positive number that divides all the numbers in the set
+without remainder.
 
 Example 1
 
-  Input: $n = 1234567
-  Output: 345
+    Input: $m = 8, $n = 24
+    Output: 1
+
+    Reason: gcd(8,24) = 8 => 2 ^ 3
 
 Example 2
 
-  Input: $n = -123
-  Output: 123
+    Input: $m = 26, $n = 39
+    Output: 0
 
-Example 3
+    Reason: gcd(26,39) = 13
 
-  Input: $n = 1
-  Output: too short
+Example 3
 
-Example 4
+    Input: $m = 4, $n = 10
+    Output: 1
 
-  Input: $n = 10
-  Output: even number of digits
+    Reason: gcd(4,10) = 2 => 2 ^ 1
 
-MY NOTES: Pretty easy, although it's not clear how to always treat negative numbers.
-Assume abs() them.
+MY NOTES: Pretty easy.  Euclid's GCD algorithm, then check if the result is a power of 2.
 
 
-TASK #2 - Validate SEDOL
+TASK #2 - Fibonacci Sequence
 
-You are given 7-characters alphanumeric SEDOL.
+You are given a positive number $n.
 
-Write a script to validate the given SEDOL. Print 1 if it is a valid SEDOL otherwise 0.
+Write a script to find how many different sequences you can create using
+Fibonacci numbers where the sum of unique numbers in each sequence are
+the same as the given number.
 
-For more information about SEDOL, please checkout https://en.wikipedia.org/wiki/SEDOL
+    Fibonacci Numbers: 1,2,3,5,8,13,21,34,55,89,..
 
 Example 1
 
-  Input: $SEDOL = '2936921'
-  Output: 1
+  Input:  $n = 16
+  Output: 4
+
+  Reason: There are 4 possible sequences that can be created using Fibonacci numbers
+  i.e. (3 + 13), (1 + 2 + 13), (3 + 5 + 8) and (1 + 2 + 5 + 8).
 
 Example 2
 
-  Input: $SEDOL = '1234567'
-  Output: 0
+  Input:  $n = 9
+  Output: 2
+
+  Reason: There are 2 possible sequences that can be created using Fibonacci numbers
+  i.e. (1 + 3 + 5) and (1 + 8).
 
 Example 3
 
-  Input: $SEDOL = 'B0YBKL9'
-  Output: 1
+  Input:  $n = 15
+  Output: 2
+
+  Reason: There are 2 possible sequences that can be created using Fibonacci numbers
+  i.e. (2 + 5 + 8) and (2 + 13).
 
-MY NOTES: Pretty easy
+MY NOTES: Pretty easy - find subsets of the first few Fibonacci numbers that sum to N.
+How many Fibonacci numbers should we consider?  Those <= N.  Then, how do we sum subsets
+of them?  Two obvious ways:
 
+1. recursive function, iterating over the Fibonacci values: each value is either in the
+   subset or not, try both possibilities.
+2. binary-counting method, iterate over every combination C from 1 .. 2**(number values)-1,
+   then sum up only the elements where the corresponding bit in C is true.
diff --git a/challenge-136/duncan-c-white/perl/ch-1.pl b/challenge-136/duncan-c-white/perl/ch-1.pl
new file mode 100755
index 0000000000..08e3486f2a
--- /dev/null
+++ b/challenge-136/duncan-c-white/perl/ch-1.pl
@@ -0,0 +1,74 @@
+#!/usr/bin/perl
+# 
+# TASK #1 - Two Friendly
+# 
+# You are given 2 positive numbers, $m and $n.
+# 
+# Write a script to find out if the given two numbers are Two Friendly.
+# 
+# Two positive numbers, m and n are two friendly when gcd(m, n) = 2 ^
+# p where p > 0. The greatest common divisor (gcd) of a set of numbers
+# is the largest positive number that divides all the numbers in the set
+# without remainder.
+# 
+# Example 1
+# 
+#     Input: $m = 8, $n = 24
+#     Output: 1
+# 
+#     Reason: gcd(8,24) = 8 => 2 ^ 3
+# 
+# Example 2
+# 
+#     Input: $m = 26, $n = 39
+#     Output: 0
+# 
+#     Reason: gcd(26,39) = 13
+# 
+# Example 3
+# 
+#     Input: $m = 4, $n = 10
+#     Output: 1
+# 
+#     Reason: gcd(4,10) = 2 => 2 ^ 1
+# 
+# MY NOTES: Pretty easy.  Euclid's GCD algorithm, then check if the result is a power of 2.
+#
+
+use strict;
+use warnings;
+use feature 'say';
+use Getopt::Long;
+use Function::Parameters;
+#use Data::Dumper;
+
+
+#
+# my $gcd = gcd( $a, $b );
+#       Compute and return the GCD (Greatest Common Denominator) of $a and $b.
+#
+fun gcd( $a, $b )
+{
+        while( $b != 0 )
+        {
+                ( $a, $b ) = ( $b, $a % $b );
+        }
+        return $a;
+}
+
+
+my $debug=0;
+die "Usage: 2-friendly N M\n" unless
+	GetOptions( "debug"=>\$debug ) && @ARGV==2;
+my( $n, $m ) = @ARGV;
+
+my $gcd = gcd( $n, $m );
+say "gcd is $gcd" if $debug;
+
+my $ispower = 0;
+for( my $twop = 2; $twop <= $gcd; $twop *= 2 )
+{
+	$ispower++ if $twop == $gcd;
+}
+
+say $ispower;
diff --git a/challenge-136/duncan-c-white/perl/ch-2.pl b/challenge-136/duncan-c-white/perl/ch-2.pl
new file mode 100755
index 0000000000..d3a4cd88e7
--- /dev/null
+++ b/challenge-136/duncan-c-white/perl/ch-2.pl
@@ -0,0 +1,124 @@
+#!/usr/bin/perl
+# 
+# TASK #2 - Fibonacci Sequence
+# 
+# You are given a positive number $n.
+# 
+# Write a script to find how many different sequences you can create using
+# Fibonacci numbers where the sum of unique numbers in each sequence are
+# the same as the given number.
+# 
+#     Fibonacci Numb