You are given a code:

def main_solution(x):
    return func_22(func_15('keuff'))

Can you predict the output of `main_solution("zopjagbtrv")` 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": "zopjagbtrv"}, "ref_output": "\u00abk\u00bb\u00abe\u00bb\u00abu\u00bb\u00abf\u00bb\u00abf", "ref_code": "def main_solution(x):\n    return func_22(func_15('keuff'))", "funcname": "main_solution"}
rule