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

1. If the string contains 'bca', delete the first occurrence entirely.
2. If the string contains 'ca' (not at the start), remove the first occurrence found after the first character.
3. If the string suffix is 'bb', delete the last two characters.
4. If the string prefix is 'ca', replace it with 'bb' and append 'c' to the end.
5. If the string ends with 'aa', replace it with 'cc'.
6. If the string length is greater than 15, remove the middle character.

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

Provide your answer as a string in the following format:

<<< "some_final_string" >>>
