You are given a code:

def main_solution(x):
    return func_20((x + 'mnwebm'), func_13('ufrdj', '_'))

Can you predict the output of `main_solution("vatc")` 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": "vatc"}, "ref_output": "vua_tfc_mrn_wde_bjm", "ref_code": "def main_solution(x):\n    return func_20((x + 'mnwebm'), func_13('ufrdj', '_'))", "funcname": "main_solution"}
rule