You are given a code:

def main_solution(x):
    return func_9(func_13('eiugpo', '-'))

Can you predict the output of `main_solution("cvvi")` 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": "cvvi"}, "ref_output": "e-i-u-g-p-oo-p-g-u-i-e", "ref_code": "def main_solution(x):\n    return func_9(func_13('eiugpo', '-'))", "funcname": "main_solution"}
rule