 Okay? So anyways, let's do the same problem here. Caffeine, but now we're not given the molecular formula we're given in the structure. Okay? We could translate the structure to the molecular formula and use that formula. But remember, degrees of unsaturation are effectively only the number of rings plus the number of pi bonds. So remember, the last problem we did, we figured out that caffeine has six units of unsaturation, right, or six degrees of unsaturation. So we can ask ourselves, well how many rings do we have and how many pi bonds do we have, and that will give us the same information. Okay? So hopefully you can see what have we got. Help me out, Alan. How many rings? You see one there? Two rings, right? And how many pi bonds? So do you see one, two, three, four, okay? So we calculate the number of rings plus the number of pi bonds. That's going to get six, so you can do it either way. Okay? Can't kill that?