So you could have the union of x and y. And the union I often view, or people often view, as or. So we're thinking about all of the elements that are in x or y. So in some ways, you can kind of imagine that we're bringing these two sets together. So this is going to be. And the key here is that a set is a collection of distinct objects. And the way we're conceptualizing things right here, this is the number 3.