You are given a code:

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

Can you predict the output of `main_solution("grrobxrkw")` 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": "grrobxrkw"}, "ref_output": "\u00abggh\u00bbr\u00abcrr\u00bbi\u00aborh\u00bbb\u00abxor\u00bbk\u00abwb\u00bb\u00abx\u00bb\u00abr\u00bb\u00abk\u00bb\u00abw\u00bb", "ref_code": "def main_solution(x):\n    return func_20(func_15(x), func_20(x, 'hcih'))", "funcname": "main_solution"}
rule