You are given a code:

def main_solution(x):
    return func_20(func_20('fxadh', 'ext'), func_15('xfh'))

Can you predict the output of `main_solution("heedmxw")` 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": "heedmxw"}, "ref_output": "f\u00abexx\u00bbx\u00abaft\u00bbd\u00abhh\u00bb", "ref_code": "def main_solution(x):\n    return func_20(func_20('fxadh', 'ext'), func_15('xfh'))", "funcname": "main_solution"}
rule