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

1. If the string contains an even number of 'b's (and at least one 'b'), append 'ab' at the end.
2. If the string prefix is 'ab', replace it with 'ca'.
3. If the string prefix is 'cb', replace it with 'aa' and delete the last character.
4. If the string prefix is 'ca', replace it with 'bb' and append 'c' to the end.
5. If the string ends with 'ca', remove the last character.
6. If the string contains 'abc', replace the first occurrence with 'cab'.

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

Provide your answer as a string in the following format:

<<< "some_final_string" >>>
