my $password = $2;
    my $limit = 3; # want to reject 4568 but not 4578

    my $counter = 0;
    my $i = 0;
    my @digits = split(//, $password);
    my $pwlength = @digits;

    for ($i = 0; $i < $pwlength - 1; $i++) {
        if ($digits[$i] + 1 == $digits[$i + 1]) {
            $counter += 1;
        } else {
            $counter = 0;
        }
        if ($counter >= $limit) {
            exit 1;
        }
    }

    $counter = 0;
    for ($i = 0; $i < $pwlength - 1; $i++) {
        if ($digits[$i] - 1 == $digits[$i + 1]) {
            $counter += 1;
        } else {
            $counter = 0;
        }
        if ($counter >= $limit) {
            exit 1;
        }
    }