You are given a code:

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

Can you predict the output of `main_solution("brlkxtvk")` 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": "brlkxtvk"}, "ref_output": "b-z-r-p-l-l-k-d-x-u-t-c-v-k", "ref_code": "def main_solution(x):\n    return func_13(func_20(x, 'zplduc'), '-')", "funcname": "main_solution"}
rule