So unsaturated means we have double bonds. Now, monounsaturated basically means we have one double bond in that hydrocarbon chain. If we're polyunsaturated, that means we have two or more of these double bonds. So two in this case and three in this particular case. Now, how do we describe the fact that we have 16 carbons and no double bonds? Well, basically, after the name, we basically write 16 to 00:16 carbon atoms and zero double bonds.