You are given a code:

def main_solution(x):
    return func_13(func_20(x, 'umgiii'), '-')

Can you predict the output of `main_solution("ysuipy")` 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": "ysuipy"}, "ref_output": "y-u-s-m-u-g-i-i-p-i-y-i", "ref_code": "def main_solution(x):\n    return func_13(func_20(x, 'umgiii'), '-')", "funcname": "main_solution"}
rule