You are given a code:

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

Can you predict the output of `main_solution("tctisbq")` 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": "tctisbq"}, "ref_output": "t-e-c-r-t-u-i-r-s-b-q", "ref_code": "def main_solution(x):\n    return func_13(func_20(x, 'erur'), '-')", "funcname": "main_solution"}
rule