And so in all of this business, we already figured out is a 3, a 7, a negative 5, and a 13. So it's essentially, start with this set and take out all the stuff that are in this set. So this is going to be equal to, so you see, we're going to have to take out a 3 out of this set. We're going to take out a 7. We're going to take out a negative 5. And we're going to take out a 13. So we're just left with the set that contains a 0.