You are given a code:

def main_solution(x):
    return ('fwmbu' + 'vuxg')

Can you predict the output of `main_solution("zvqpxatl")` 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": "zvqpxatl"}, "ref_output": "fwmbuvuxg", "ref_code": "def main_solution(x):\n    return ('fwmbu' + 'vuxg')", "funcname": "main_solution"}
rule