You are given a code:

def main_solution(x):
    return func_13(func_5('mmbneg', 'cyex'), '-')

Can you predict the output of `main_solution("bakr")` 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": "bakr"}, "ref_output": "c-y-e-x-m-m-b-n-e-g", "ref_code": "def main_solution(x):\n    return func_13(func_5('mmbneg', 'cyex'), '-')", "funcname": "main_solution"}
rule