You are given a code:

def main_solution(x):
    return func_17(('ybtfbs' + 'ceamm'))

Can you predict the output of `main_solution("fsie")` 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": "fsie"}, "ref_output": "mmaecsbftby", "ref_code": "def main_solution(x):\n    return func_17(('ybtfbs' + 'ceamm'))", "funcname": "main_solution"}
rule