You are given a code:

def main_solution(x):
    return func_13(func_5(x, 'ciy'), '-')

Can you predict the output of `main_solution("vyvnggibg")` 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": "vyvnggibg"}, "ref_output": "c-i-y-v-y-v-n-g-g-i-b-g", "ref_code": "def main_solution(x):\n    return func_13(func_5(x, 'ciy'), '-')", "funcname": "main_solution"}
rule