This whole crazy business, all of this crazy business, has simplified to this set right over here. Now, we want to find the relative complement of this business in A. So let me pick another color here. So we want to find the relative complement of this business in A. So now I'll just actually write out the set. 3, 7, negative 5, 13. Actually, let me write out both of them, just to make it, just so that we can really just visualize them both right over here.