You are given a code:

def main_solution(x):
    return func_20(func_20('pyndvu', x), func_15('ykcsb'))

Can you predict the output of `main_solution("tjaknkzpo")` 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": "tjaknkzpo"}, "ref_output": "p\u00abtyy\u00bbj\u00abnka\u00bbd\u00abkcv\u00bbn\u00abusk\u00bbz\u00abpbo\u00bb", "ref_code": "def main_solution(x):\n    return func_20(func_20('pyndvu', x), func_15('ykcsb'))", "funcname": "main_solution"}
rule