5 use experimental 'multidimensional';
15 my $c = substr($_, $i, 1);
16 unshift @{ $stacks[$st] }, $c if $c =~ /[A-Z]/;
25 my ($amount, $src, $dst) = /(\d+)/g;
26 push @{ $stacks[$dst-1] }, pop @{ $stacks[$src-1] } for 1 .. $amount;
29 for my $st (@stacks) {