So here we have five carbons. Our N is five. We have eleven H atoms, but we also have N atoms. So let's go back to our rules. According to rule number three, remove nitrogens along with one H.
So every time we remove a nitrogen, we remove one H. So that means we no longer have eleven HS, but we have eleven minus three HS. Because if we remove three ends, we have to remove three H's.