You are given a code:

def main_solution(x):
    return func_20(func_9('bwylw'), func_15('lqwkfx'))

Can you predict the output of `main_solution("rvnvvq")` 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": "rvnvvq"}, "ref_output": "b\u00abwly\u00bbl\u00abwqw\u00bbl\u00abyww\u00bbb\u00abk\u00bb\u00abf\u00bb\u00abx\u00bb", "ref_code": "def main_solution(x):\n    return func_20(func_9('bwylw'), func_15('lqwkfx'))", "funcname": "main_solution"}
rule