You are given a code:

def main_solution(x):
    return func_13(func_20(x, 'cjn'), '-')

Can you predict the output of `main_solution("bkgnafz")` 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": "bkgnafz"}, "ref_output": "b-c-k-j-g-n-n-a-f-z", "ref_code": "def main_solution(x):\n    return func_13(func_20(x, 'cjn'), '-')", "funcname": "main_solution"}
rule