What topic for the thesis to choose?

Question

Programming

I study applied mathematics and computer science, I can’t find anything interesting (unusual and preferably not very complicated in software implementation) for myself.
There must be a mat part and its software implementation. I don’t have a preference for a programming language (I still have a year before my diploma, so I can try myself in something new).
I would like to hear some advice on the subject area (where to stick and what to see) or ready-made options.
Z.Y. Thanks in advance)