You are given a code:

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

Can you predict the output of `main_solution("xjndervu")` 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": "xjndervu"}, "ref_output": "\u00abuxu\u00bbw\u00abijg\u00bbd\u00abxnj\u00bbn\u00abdde\u00bbr\u00abveu\u00bb\u00abr\u00bb\u00abv\u00bb\u00abu\u00bb", "ref_code": "def main_solution(x):\n    return func_20(func_15(x), ('uuwigd' + x))", "funcname": "main_solution"}
rule