You are given a code:

def main_solution(x):
    return func_13('soyr', '|')

Can you predict the output of `main_solution("mzxxqbokn")` 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": "mzxxqbokn"}, "ref_output": "s|o|y|r", "ref_code": "def main_solution(x):\n    return func_13('soyr', '|')", "funcname": "main_solution"}
rule