Hi- what language was this? I agree with you that the answer should have been 6.

Thanks.

;-)

Python version is a translation from @suic
I've checked the test code and I haven't find out any error(Please forgive me for my poor Python skills)
I modified something of random tests:

1. Shorten the string length
2. Prohibit the generation of characters other than letters and exclamation marks
3. Added some information to display, including the original string, reference results, and user results

Which language are you using?