5 my @map = map { chomp; [ split // ] } <>;
6 my $xmax = $#{ $map[0] };
10 for my $y (0 .. $ymax) {
11 for my $x (0 .. $xmax) {
12 next if $map[$y][$x] ne 'O';
14 $y1-- while $y1 && $map[$y1-1][$x] eq '.';
19 $sum += $ymax + 1 - $y1;
23 say join('', @$_) for @map;