Classification of stories based on comments

Hi everybody,

I am working on a student project and I aim to classify stories just by comments which are left below. Comments have a tree-like structure and therefore I am looking for a way to leverage that instead of just concatenating text and using that as input. I would like to use a pre-trained model but I am not sure how that will work since I didn’t find any model that works with nested text structure on input. What are the options that I have and what is the best practice for this kind of problem?