You are given a code:

def main_solution(x):
    return func_20((x + x), func_15('hpwnj'))

Can you predict the output of `main_solution("nfxtgo")` 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": "nfxtgo"}, "ref_output": "n\u00abfhx\u00bbt\u00abgpo\u00bbn\u00abfwx\u00bbt\u00abgno\u00bb\u00abj\u00bb", "ref_code": "def main_solution(x):\n    return func_20((x + x), func_15('hpwnj'))", "funcname": "main_solution"}
rule