You are given a code:

def main_solution(x):
    return func_20(func_20(x, 'wfb'), func_15('hanlla'))

Can you predict the output of `main_solution("adrbthln")` 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": "adrbthln"}, "ref_output": "a\u00abwhd\u00bbf\u00abrab\u00bbb\u00abtnh\u00bbl\u00abnl\u00bb\u00abl\u00bb\u00aba\u00bb", "ref_code": "def main_solution(x):\n    return func_20(func_20(x, 'wfb'), func_15('hanlla'))", "funcname": "main_solution"}
rule