It's hollowed out in the middle. You can kind of use the y equals x squared part kind of hollows out the middle, and it's really the stuff in between that forms the wall of this kind of rotated shape. So let's think about how we can figure out the volume. And we're going to do it using the disk method, sometimes called the ring method. Actually, it's going to be more of the washer method to do this one right over here. So we're rotating around a vertical line. We want to use our disk or ring or washer method.