A levels for mathematical(computer science) or medical line

I am still undecided about my career path but have several work experience placements over the next year including shifts at a hospital/care home and working on computer science projects (some of which I've already done this summer). The trouble is, I won't be able to change my A-level subjects once I've decided, so what is the best combination of A-level subjects to keep my options open for both of them? I also plan to do an EPQ after the initial work experience.

I plan to do 4 A-levels and have decided on maths and further maths but the remaining 2 can be from biology, chemistry, physics and economics, so which 2 should I pick? Or would it be a better idea to do 5?