You are given a code:

def main_solution(x):
    return func_20(func_15(x), func_13('auuw', '_'))

Can you predict the output of `main_solution("zdings")` 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": "zdings"}, "ref_output": "\u00abaz_\u00bbu\u00ab_du\u00bb_\u00abwi\u00bb\u00abn\u00bb\u00abg\u00bb\u00abs\u00bb", "ref_code": "def main_solution(x):\n    return func_20(func_15(x), func_13('auuw', '_'))", "funcname": "main_solution"}
rule