You are given a code:

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

Can you predict the output of `main_solution("ydxbpnuue")` 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": "ydxbpnuue"}, "ref_output": "\u00abyqd\u00bbx\u00abbhp\u00bbn\u00abuzu\u00bbe\u00abvov\u00bbj\u00abl\u00bb\u00abd\u00bb", "ref_code": "def main_solution(x):\n    return func_20(func_15('qhzold'), (x + 'vvj'))", "funcname": "main_solution"}
rule