You are given a code:

def main_solution(x):
    return (('vxpbqc' + 'vief') + func_19('nizpz', 2))

Can you predict the output of `main_solution("onfegwsa")` 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": "onfegwsa"}, "ref_output": "vxpbqcviefzpzni", "ref_code": "def main_solution(x):\n    return (('vxpbqc' + 'vief') + func_19('nizpz', 2))", "funcname": "main_solution"}
rule