You are given a code:

def main_solution(x):
    return func_20(func_20('ewaghw', 'httef'), func_15(x))

Can you predict the output of `main_solution("yvaa")` 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": "yvaa"}, "ref_output": "e\u00abhyw\u00bbt\u00abavt\u00bbg\u00abeah\u00bbf\u00abwa\u00bb", "ref_code": "def main_solution(x):\n    return func_20(func_20('ewaghw', 'httef'), func_15(x))", "funcname": "main_solution"}
rule