You are given a code:

def main_solution(x):
    return func_13(('jindig' + x), '-')

Can you predict the output of `main_solution("aktgpe")` 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": "aktgpe"}, "ref_output": "j-i-n-d-i-g-a-k-t-g-p-e", "ref_code": "def main_solution(x):\n    return func_13(('jindig' + x), '-')", "funcname": "main_solution"}
rule