You are given a code:

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

Can you predict the output of `main_solution("skguhrjj")` 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": "skguhrjj"}, "ref_output": "s-k-g-u-h-r-j-j-h-t-d-u-t", "ref_code": "def main_solution(x):\n    return func_13((x + 'htdut'), '-')", "funcname": "main_solution"}
rule