You are given a code:

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

Can you predict the output of `main_solution("dxrd")` 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": "dxrd"}, "ref_output": "d-y-x-k-r-o-d-t", "ref_code": "def main_solution(x):\n    return func_13(func_20(x, 'ykot'), '-')", "funcname": "main_solution"}
rule