You are given a code:

def main_solution(x):
    return func_20(func_20('ghmb', 'mgxcj'), func_15('zxdu'))

Can you predict the output of `main_solution("pqbxvfucj")` 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": "pqbxvfucj"}, "ref_output": "g\u00abmzh\u00bbg\u00abmxx\u00bbb\u00abcdj\u00bb\u00abu\u00bb", "ref_code": "def main_solution(x):\n    return func_20(func_20('ghmb', 'mgxcj'), func_15('zxdu'))", "funcname": "main_solution"}
rule