You are given a code:

def main_solution(x):
    return (('sto' + 'vsw') + func_13('ifduee', '|'))

Can you predict the output of `main_solution("mfpx")` 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": "mfpx"}, "ref_output": "stovswi|f|d|u|e|e", "ref_code": "def main_solution(x):\n    return (('sto' + 'vsw') + func_13('ifduee', '|'))", "funcname": "main_solution"}
rule