You are given a code:

def main_solution(x):
    return (func_15('vqzb') + func_5('gqv', 'faq'))

Can you predict the output of `main_solution("hkgu")` 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": "hkgu"}, "ref_output": "\u00abv\u00bb\u00abq\u00bb\u00abz\u00bb\u00abb\u00bbfaqgqv", "ref_code": "def main_solution(x):\n    return (func_15('vqzb') + func_5('gqv', 'faq'))", "funcname": "main_solution"}
rule