You are given a code:

def main_solution(x):
    return func_20('fhzin', 'uyifpo')

Can you predict the output of `main_solution("txnzpbv")` 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": "txnzpbv"}, "ref_output": "fuhyziifnpo", "ref_code": "def main_solution(x):\n    return func_20('fhzin', 'uyifpo')", "funcname": "main_solution"}
rule