You are given a code:

def main_solution(x):
    return (func_13('ecrbgc', '-') + func_13('bjjhng', '_'))

Can you predict the output of `main_solution("feggxv")` 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": "feggxv"}, "ref_output": "e-c-r-b-g-cb_j_j_h_n_g", "ref_code": "def main_solution(x):\n    return (func_13('ecrbgc', '-') + func_13('bjjhng', '_'))", "funcname": "main_solution"}
rule