No way your soo lucky, I wish i just have them two exams.
But honestly the best way in my opinion to revise is to just do past papers you can usually find them on the exam boards website. You should also time yourself to make sure you can answer all the questions in the time limit. But it worked for me as I didnt do any my first year and got a U but did loads of them in my second year and I got an A :).
I just do past papers after past papers after past papers and then do them all again! Personally that is what I find to do with maths...but you are so lucky I have 5 other big exams to do on top of c3 and c4! You've got so much time to concentrate on Maths so good luck!