You are given a code:

def main_solution(x):
    return func_20(func_20(x, 'iav'), func_15('hgmk'))

Can you predict the output of `main_solution("nnxlplpxi")` 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": "nnxlplpxi"}, "ref_output": "n\u00abihn\u00bba\u00abxgv\u00bbl\u00abpml\u00bbp\u00abxki\u00bb", "ref_code": "def main_solution(x):\n    return func_20(func_20(x, 'iav'), func_15('hgmk'))", "funcname": "main_solution"}
rule