You are given a code:

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

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