You are given a code:

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

Can you predict the output of `main_solution("wrtqwh")` 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": "wrtqwh"}, "ref_output": "w-r-t-q-w-h-y-v-q", "ref_code": "def main_solution(x):\n    return func_13((x + 'yvq'), '-')", "funcname": "main_solution"}
rule