You are given a code:

def main_solution(x):
    return func_22('ntee')

Can you predict the output of `main_solution("iuup")` 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": "iuup"}, "ref_output": "ntee", "ref_code": "def main_solution(x):\n    return func_22('ntee')", "funcname": "main_solution"}
rule