Cycle through the following operations one at a time until no further operations can be performed:

1. If the string ends with 'aa', replace it with 'cc'.
2. If the string length is greater than 15, remove the middle character.
3. If the string prefix is 'bc', delete the first two characters and append 'aa' to the end.
4. If the string contains 'bca', delete the first occurrence entirely.
5. If the string prefix is 'aa', remove the first character.
6. If the string starts with 'ac', replace the first two characters with 'zz'.

For the string "acaaaababcaccbbaaab", what is the final string after performing all operations?

Provide your answer as a string in the following format:

<<< "some_final_string" >>>
