A level choices? Help please!

Hey

Can someone help me decide if I should do Physics or Further Maths at A-Level. I would like to study Medicine at University and hence I must take Biology and Chemistry. I am also definitely taking Maths because I enjoy it and think that it will be useful. I plan to take four A-Levels but I don't know if it would be better to take Physics or Further Maths. I am interested in both and get good grades in both. Physics is not as relevant to what I plan to do but it may open up my options in case I decide to do something else? What should I choose?