You are given a code:

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

Can you predict the output of `main_solution("fwf")` 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": "fwf"}, "ref_output": "i-v-r-a-q-j-m-m-c-w", "ref_code": "def main_solution(x):\n    return func_13(func_20('irqm', 'vajmcw'), '-')", "funcname": "main_solution"}
rule