You are given a code:

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

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