You are given a code:

def main_solution(x):
    return func_13((x + 'nmiao'), '-')

Can you predict the output of `main_solution("yyufqvwv")` 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": "yyufqvwv"}, "ref_output": "y-y-u-f-q-v-w-v-n-m-i-a-o", "ref_code": "def main_solution(x):\n    return func_13((x + 'nmiao'), '-')", "funcname": "main_solution"}
rule