This is a solution to problem 25 on the hard interview questions node. If you have not read the question, the following will make no sense to you:

Cut each pill in half and divide them into two piles. Then, take another A pill from the bottle, cut it in half, and put each half in one of the piles. Now, each pile contains two halves from each type of pill, so you just take one of the piles (and the other the next day).