use strict; use warnings; my $l = <>; chomp $l; my @arr = split//,$l; my @wcount; push @wcount, 0; for (my $i = 0; $i < @arr; $i++) { my $isw = $arr[$i] eq 'w' ? 1 : 0; push @wcount, $wcount[$i] + $isw; } my $maxw = $wcount[@wcount - 1]; my $ans = 0; for (my $i = 0; $i < @arr; $i++) { my $right_wcnt = $maxw - $wcount[$i + 1]; $ans += $right_wcnt * ($right_wcnt - 1) / 2 if $arr[$i] eq 'c'; } print $ans;