You are given a code:

def main_solution(x):
    return func_20('mlmwx', 'qumv')

Can you predict the output of `main_solution("tdpz")` 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": "tdpz"}, "ref_output": "mqlummwvx", "ref_code": "def main_solution(x):\n    return func_20('mlmwx', 'qumv')", "funcname": "main_solution"}
rule