You are given a code:

def main_solution(x):
    return func_4('rfcoa')

Can you predict the output of `main_solution("gilywgy")` 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": "gilywgy"}, "ref_output": "rfcoa", "ref_code": "def main_solution(x):\n    return func_4('rfcoa')", "funcname": "main_solution"}
rule