You are given a code:

def main_solution(x):
    return (func_20('opvpoc', 'xvtzf') + ('ugq' + 'hvzwvy'))

Can you predict the output of `main_solution("yzgqppo")` 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": "yzgqppo"}, "ref_output": "oxpvvtpzofcugqhvzwvy", "ref_code": "def main_solution(x):\n    return (func_20('opvpoc', 'xvtzf') + ('ugq' + 'hvzwvy'))", "funcname": "main_solution"}
rule