You are given a code:

def main_solution(x):
    return func_5(func_20('cnvj', 'ipxpy'), 'zak')

Can you predict the output of `main_solution("nehnnbsjzv")` 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": "nehnnbsjzv"}, "ref_output": "zakcinpvxjpy", "ref_code": "def main_solution(x):\n    return func_5(func_20('cnvj', 'ipxpy'), 'zak')", "funcname": "main_solution"}
rule