 they have to all be different or largely all different. So a lot of the times, engineers and architects will shy away from something like that roof because you've got to make so many custom-shaped triangles and it's very hard to have spare bits of glass because you've got to have basically a different spare for every spot or you have to get one newly made every time there's a breakage. So engineers and architects like to have the same triangle over and over, but that limits...