#!/usr/bin/perl use strict; use warnings; my $file = "input"; open my $in, "<", $file or die "Failed to open ‘$file’: $!"; my ($x, $y) = (0) x 2; while (<$in>) { chomp; my %freq; $freq{$_}++ for split //; $x++ if grep { $_ == 2 } values %freq; $y++ if grep { $_ == 3 } values %freq; } close $in; printf "%d\n", $x * $y;