You are given a code:

def main_solution(x):
    return func_20(func_15('qnmi'), (x + 'bytg'))

Can you predict the output of `main_solution("mvv")` 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": "mvv"}, "ref_output": "\u00abmqv\u00bbv\u00abbny\u00bbt\u00abgm\u00bb\u00abi\u00bb", "ref_code": "def main_solution(x):\n    return func_20(func_15('qnmi'), (x + 'bytg'))", "funcname": "main_solution"}
rule