So let's begin with this sugar here. This sugar contains carbon number three, that contains our oxygen. And this oxygen attached to carbon number three is attached to a phosphate group. And that phosphate group is in turn attached to this oxygen here that is linked to carbon number five of this adjacent sugar. And that's exactly what a three to five linkage actually means. So we have this oxygen on the third carbon, is linked to this oxygen on the fifth carbon of that adjacent sugar.