You are given a code:

def main_solution(x):
    return func_20(func_15('fgnrgz'), func_1(x, 4))

Can you predict the output of `main_solution("dxrpmbkf")` 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": "dxrpmbkf"}, "ref_output": "\u00abdfx\u00bbr\u00abpgm\u00bbb\u00abknf\u00bbd\u00abxrr\u00bbp\u00abmgb\u00bbk\u00abfzd\u00bbxrpmbkfdxrpmbkf", "ref_code": "def main_solution(x):\n    return func_20(func_15('fgnrgz'), func_1(x, 4))", "funcname": "main_solution"}
rule