You are given a code:

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

Can you predict the output of `main_solution("obakb")` 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": "obakb"}, "ref_output": "o\u00abovb\u00bbb\u00abama\u00bbk\u00abkrb\u00bbb\u00abc\u00bb\u00abs\u00bb\u00aby\u00bb", "ref_code": "def main_solution(x):\n    return func_20(func_20(x, x), func_15('vmrcsy'))", "funcname": "main_solution"}
rule