You are given a code:

def main_solution(x):
    return func_5(func_20('bqvmw', 'zpz'), 'ytn')

Can you predict the output of `main_solution("xtr")` 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": "xtr"}, "ref_output": "ytnbzqpvzmw", "ref_code": "def main_solution(x):\n    return func_5(func_20('bqvmw', 'zpz'), 'ytn')", "funcname": "main_solution"}
rule