You are given a code:

def main_solution(x):
    return func_20(func_15('dbzsqq'), func_9('jxi'))

Can you predict the output of `main_solution("fmmbkuspen")` without writing any code? Please reason and put your final answer in the following json format: {"output": <your output>}, where <your output> should be the final string.
user
{"ref_input": {"x": "fmmbkuspen"}, "ref_output": "\u00abjdx\u00bbi\u00abibx\u00bbj\u00abz\u00bb\u00abs\u00bb\u00abq\u00bb\u00abq\u00bb", "ref_code": "def main_solution(x):\n    return func_20(func_15('dbzsqq'), func_9('jxi'))", "funcname": "main_solution"}
rule