You are given a code:

def main_solution(x):
    return func_20(func_20(x, x), func_15('gvvhpi'))

Can you predict the output of `main_solution("xtpsnujk")` 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": "xtpsnujk"}, "ref_output": "x\u00abxgt\u00bbt\u00abpvp\u00bbs\u00absvn\u00bbn\u00abuhu\u00bbj\u00abjpk\u00bbk\u00abi\u00bb", "ref_code": "def main_solution(x):\n    return func_20(func_20(x, x), func_15('gvvhpi'))", "funcname": "main_solution"}
rule