You are given a code:

def main_solution(x):
    return func_15(func_20('koixz', 'tmw'))

Can you predict the output of `main_solution("nen")` 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": "nen"}, "ref_output": "\u00abk\u00bb\u00abt\u00bb\u00abo\u00bb\u00abm\u00bb\u00abi\u00bb\u00abw\u00bb\u00abx\u00bb\u00abz\u00bb", "ref_code": "def main_solution(x):\n    return func_15(func_20('koixz', 'tmw'))", "funcname": "main_solution"}
rule