You are given a code:

def main_solution(x):
    return ('drgoi' + 'yvpv')

Can you predict the output of `main_solution("sbn")` 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": "sbn"}, "ref_output": "drgoiyvpv", "ref_code": "def main_solution(x):\n    return ('drgoi' + 'yvpv')", "funcname": "main_solution"}
rule