You are given a code:

def main_solution(x):
    return func_20(func_15('mnrrrz'), ('burw' + x))

Can you predict the output of `main_solution("jrvupm")` 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": "jrvupm"}, "ref_output": "\u00abbmu\u00bbr\u00abwnj\u00bbr\u00abvru\u00bbp\u00abmr\u00bb\u00abr\u00bb\u00abz\u00bb", "ref_code": "def main_solution(x):\n    return func_20(func_15('mnrrrz'), ('burw' + x))", "funcname": "main_solution"}
rule