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diff --git a/challenge-226/jo-37/perl/ch-2.pl b/challenge-226/jo-37/perl/ch-2.pl
new file mode 100755
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+++ b/challenge-226/jo-37/perl/ch-2.pl
@@ -0,0 +1,59 @@
+#!/usr/bin/perl -s
+
+use v5.24;
+use Test2::V0;
+
+our ($tests, $examples);
+
+run_tests() if $tests || $examples;	# does not return
+
+die <<EOS unless @ARGV;
+usage: $0 [-examples] [-tests] [N...]
+
+-examples
+    run the examples from the challenge
+ 
+-tests
+    run some tests
+
+N...
+    list of non-negative numbers
+
+EOS
+
+
+### Input and Output
+
+say zero_array(@ARGV);
+
+
+### Implementation
+
+# To turn all elements to zero following the given rules, we need as
+# many steps as there are distinct non-zero elements in the list.
+sub zero_array {
+    (\my %v)->@{@_} = ();
+    scalar grep $_, keys %v;
+}
+
+
+### Examples and tests
+
+sub run_tests {
+    SKIP: {
+        skip "examples" unless $examples;
+
+        is zero_array(1, 5, 0, 3, 5), 3, 'example 1';
+        is zero_array(0), 0, 'example 2';
+        is zero_array(2, 1, 4, 0, 3), 4, 'example 3';
+    }
+
+    SKIP: {
+        skip "tests" unless $tests;
+
+        is zero_array(1, 2, 1, 2), 2, 'no zero';
+	}
+
+    done_testing;
+    exit;
+}