You are given a code:

def main_solution(x):
    return func_20(func_15('nyqtu'), func_20(x, 'gycz'))

Can you predict the output of `main_solution("rgketmvv")` 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": "rgketmvv"}, "ref_output": "\u00abrng\u00bbg\u00abyyk\u00bbc\u00abeqz\u00bbt\u00abmtv\u00bbv\u00abu\u00bb", "ref_code": "def main_solution(x):\n    return func_20(func_15('nyqtu'), func_20(x, 'gycz'))", "funcname": "main_solution"}
rule