And of course, we still have the 1 third out here, and we're still multiplying by this h over here. So let me see if I can simplify this. So this gives us 1 third times pi h squared over 4 times another h, which is equal to, we have pi h to the third power over 12. So that is our volume. Now what we want to do is relate how fast the volume is changing with respect to time and how fast the height is changing with respect to time. So we care with respect to time. Since we care so much about what's happening with respect to time, let's take the derivative of both sides of this equation with respect to time.