You are given a code:

def main_solution(x):
    return func_20(func_15(x), func_23('ppnblq', 3))

Can you predict the output of `main_solution("gkzdzldkz")` 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": "gkzdzldkz"}, "ref_output": "\u00abpgp\u00bbn\u00abbkl\u00bbq\u00ab1z\u00bb\u00abd\u00bb\u00abz\u00bb\u00abl\u00bb\u00abd\u00bb\u00abk\u00bb\u00abz\u00bb", "ref_code": "def main_solution(x):\n    return func_20(func_15(x), func_23('ppnblq', 3))", "funcname": "main_solution"}
rule