You are given a code:

def main_solution(x):
    return func_20(func_20('yfs', 'ieo'), func_15('fmkw'))

Can you predict the output of `main_solution("znukrb")` 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": "znukrb"}, "ref_output": "y\u00abiff\u00bbe\u00absmo\u00bb\u00abk\u00bb\u00abw\u00bb", "ref_code": "def main_solution(x):\n    return func_20(func_20('yfs', 'ieo'), func_15('fmkw'))", "funcname": "main_solution"}
rule