You are given a code:

def main_solution(x):
    return (func_23('rex', 3) + func_13('ydsgc', '-'))

Can you predict the output of `main_solution("bigyol")` 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": "bigyol"}, "ref_output": "rex1y-d-s-g-c", "ref_code": "def main_solution(x):\n    return (func_23('rex', 3) + func_13('ydsgc', '-'))", "funcname": "main_solution"}
rule