You are given a code:

def main_solution(x):
    return func_20(func_20(x, 'yiung'), func_15('pzuupb'))

Can you predict the output of `main_solution("qzljrbchzk")` 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": "qzljrbchzk"}, "ref_output": "q\u00abypz\u00bbi\u00ablzu\u00bbj\u00abnur\u00bbg\u00abbuc\u00bbh\u00abzpk\u00bb\u00abb\u00bb", "ref_code": "def main_solution(x):\n    return func_20(func_20(x, 'yiung'), func_15('pzuupb'))", "funcname": "main_solution"}
rule