You are given a code:

def main_solution(x):
    return func_13(('rpgzum' + x), '|')

Can you predict the output of `main_solution("mtclhvnlz")` 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": "mtclhvnlz"}, "ref_output": "r|p|g|z|u|m|m|t|c|l|h|v|n|l|z", "ref_code": "def main_solution(x):\n    return func_13(('rpgzum' + x), '|')", "funcname": "main_solution"}
rule