You are given a code:

def main_solution(x):
    return func_5(func_9('oqbo'), 'xrj')

Can you predict the output of `main_solution("ezqtgqbkv")` 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": "ezqtgqbkv"}, "ref_output": "xrjoqboobqo", "ref_code": "def main_solution(x):\n    return func_5(func_9('oqbo'), 'xrj')", "funcname": "main_solution"}
rule