 Okay, so let's try this structure. What kind of compound is this one? A bicyclo. A bicyclo again, okay. So, I'm going to write bicyclo because we're trying to name this. How many carbons are in this thing? So, what kind of bicyclo is it? It's a decking. So, it's a decking. And in all bicyclos, right, we're going to have these brackets. And in there, we're going to have how many numbers? Three. Three numbers, okay. And those three numbers are going to be the numbers that are the number of carbons where? The bridge head. From the bridge head, right? From the bridge head. And we're going to label them in what order? For them. Largest to smallest. Okay, so let's try that, okay. So, what's going to be the largest number that we'll put? Four. Four. In fact, there's two of them, right? Two of them, right? So, let's count them. So, the bridge heads are here and there. Am I correct? Yes. One, two, three, four. And one, two, three, four. So, we put four dot four. But I thought we were going to put three numbers. What's the third number? Zero. Zero, very good, right? Because there's no carbons this way in between the bridge head. Okay. Does anybody remember the common name of this molecule? Anybody remember? Not a single person, huh? How about if I do this? Does this help? Trans-deckling. How close? Trans-deckling. Deckling. Trans-deckling, okay. Remember, it's trans, right? Because this carbon here is up and this one here is down, okay? So, it's trans because of the carbons. Trans-deckling. Any questions on that? Wonderful.