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+# Write a script to print first 10 Sexy Prime Pairs.
+# Sexy primes are prime numbers that differ from each other by 6.
+# For example, the numbers 5 and 11 are both sexy primes, because 11 - 5 = 6.
+# The term “sexy prime” is a pun stemming from the Latin word for six: sex.
+# For more information, please checkout wiki page.
+
+use strict;
+use warnings;
+
+# just reusing comments and code from previous challenges:
+
+# we will need a function to test primality. As this is a
+# challenge and so far not very concerned about performance,
+# I will go for the "regex" primality test.
+# you can find more information at
+# https://iluxonchik.github.io/regular-expression-check-if-number-is-prime/
+# but let just say that to test if some n number is prime, we build a string
+# of n characters (with <char> x n), and let the regex engine try to divide
+# it in more than one equal parts of at least 2 chars. So if
+# we are not successful on that it means it is prime.
+# we use a digit as the char as we don't have to quote it. Any digit will
+# do, so we just pick "7"
+
+sub is_prime {
+    return ( 7 x shift ) !~ /^(77+)\1+$/;
+}
+
+# note that we should ensure that argument is greater than 1 before
+# calling this sub, because it will uncorrectly return 1 for both 0 and 1
+
+my $q = shift // 10; # this is the amount of sexy primes we are printing
+
+my $candidate = 3; # first number that makes sense to check
+
+while ($q) { # i.e. while $q is > 0
+    if (is_prime($candidate) && is_prime($candidate+6)) {
+        printf "Found sexy primes: %u and %u\n", $candidate, $candidate+6;
+        $q--;   # one less to go
+    }
+    $candidate+= 2; # skip even candidates as they dont make sense
+}