You are given a code:

def main_solution(x):
    return (func_15('eejw') + func_4('vwbglt'))

Can you predict the output of `main_solution("nqtldxdz")` 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": "nqtldxdz"}, "ref_output": "\u00abe\u00bb\u00abe\u00bb\u00abj\u00bb\u00abw\u00bbvwbglt", "ref_code": "def main_solution(x):\n    return (func_15('eejw') + func_4('vwbglt'))", "funcname": "main_solution"}
rule