Isolating values in large set by subtracting two smaller sets within, using Matching?

I have three larges columns of skus, we'll call them Set A, B, C. Set A is 600 skus, and includes all(or just about) of Set B, and all of Set C. It also has some left over, and these are the items I'm attempting to find and isolate. So I want to use Matching or best method to create a Set D= Set C- Set A - Set B. Thanks from a novice amateur excel user.