You are given a code:

def main_solution(x):
    return (('mmhw' + 'pyfe') + func_20('pap', 'mqx'))

Can you predict the output of `main_solution("nvwdaaz")` 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": "nvwdaaz"}, "ref_output": "mmhwpyfepmaqpx", "ref_code": "def main_solution(x):\n    return (('mmhw' + 'pyfe') + func_20('pap', 'mqx'))", "funcname": "main_solution"}
rule