You are given a code:

def main_solution(x):
    return func_20('bfm', 'jyvr')

Can you predict the output of `main_solution("ffmbofhtp")` 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": "ffmbofhtp"}, "ref_output": "bjfymvr", "ref_code": "def main_solution(x):\n    return func_20('bfm', 'jyvr')", "funcname": "main_solution"}
rule