So we name our alkene simply one. Butane so the in part simply means our double bond is found on the first position and we have a four carbon backbone. So butte means we have a four carbon backbone. So let's go to example B. In example B, we have a symmetrical molecule, a symmetrical compound. And that simply means that it doesn't matter if we begin on this end or this end, we get the same alkyne, the same alkyne name.