You are given a code:

def main_solution(x):
    return func_20(func_20('pkhu', x), func_15('cajngm'))

Can you predict the output of `main_solution("amfmvf")` 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": "amfmvf"}, "ref_output": "p\u00aback\u00bbm\u00abhaf\u00bbu\u00abmjv\u00bbf\u00abn\u00bb\u00abg\u00bb\u00abm\u00bb", "ref_code": "def main_solution(x):\n    return func_20(func_20('pkhu', x), func_15('cajngm'))", "funcname": "main_solution"}
rule