# Get the unique list of suits in the first 4 cards
my %suit = map {$_ => undef} unpack('xAxAxAxA', $str);

# If all the same, count 1 per card
if (keys %suit == 1) {
    $score += 4;

    # If cut-card matches, add 1 for that too
    $score += 1 if substr($str, 1, 1) eq substr($str, -1, 1);
}