You are given a code:

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

Can you predict the output of `main_solution("qdjagknq")` 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": "qdjagknq"}, "ref_output": "p\u00abfvb\u00bbq\u00abdvj\u00bba\u00abgzk\u00bbn\u00abqc\u00bb\u00abp\u00bb\u00abh\u00bb", "ref_code": "def main_solution(x):\n    return func_20(('pfb' + x), func_15('vvzcph'))", "funcname": "main_solution"}
rule