And on the left hand side, well we just apply the chain rule. So this would be g prime of h of x, g prime of h of x, times h prime of x, that's just the chain rule right over there, and that would be equal to, what's the derivative with respect to x of x? Well that's just going to be equal to one. So now it's interesting. We need to figure out what h prime of three is. So we can figure out what h of three is, and then we can use that to figure out what g prime of whatever h, g prime of h of three is. And so we should be able to figure out h prime of x.