You are given a code:

def main_solution(x):
    return func_20(('vtoa' + x), func_9('wmxou'))

Can you predict the output of `main_solution("wwon")` 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": "wwon"}, "ref_output": "vwtmoxaowuwuoonxmw", "ref_code": "def main_solution(x):\n    return func_20(('vtoa' + x), func_9('wmxou'))", "funcname": "main_solution"}
rule