You are given a code:

def main_solution(x):
    return (func_20('oul', x) + func_13('epttfd', '-'))

Can you predict the output of `main_solution("hgzx")` 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": "hgzx"}, "ref_output": "ohuglzxe-p-t-t-f-d", "ref_code": "def main_solution(x):\n    return (func_20('oul', x) + func_13('epttfd', '-'))", "funcname": "main_solution"}
rule