You are given a code:

def main_solution(x):
    return ('eky' + 'jvvl')

Can you predict the output of `main_solution("bfn")` 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": "bfn"}, "ref_output": "ekyjvvl", "ref_code": "def main_solution(x):\n    return ('eky' + 'jvvl')", "funcname": "main_solution"}
rule