sub theLoveLetterMystery {
    my @s = split("", shift);
    my $cnt = 0;
    my $k = 0;
    my $left_part = 0;
    my $right_part = 0;
    while ($k < int(scalar(@s) / 2)) {
        $left_part = ord($s[$k]);
        $right_part = ord($s[scalar(@s) - $k - 1]);
        while ($left_part != $right_part){
            if ($left_part < $right_part) {
                $cnt++;
                $right_part -= 1;
            } elsif ($left_part > $right_part) {
                $cnt++;
                $left_part -= 1;
            }
        }
        $k++;
    }
    return $cnt;

}