And let's take one more. And place it like so all these guys have different structures, but identical molecular formulas, so they're all isomers. So let's go to step four, because we're essentially done here, if we rearrange them in some other way, we're going to get back on the same molecule as before. So let's go to step four. In step four, I have dot, dot, dot, because we're simply removing not one or two, but three carbons from the end. So we're moving one, two, three.