And we basically form and extend it. So we extend that primer by one and we also form the UDP, which is basically shown here. So UDP is urine diphosphate, it contains the uridine and two phosphate groups. And we're going to use the UDP in the last step, as we'll see in just a moment. Now, once we form that glycogen, that linear unbranched glycogen, we want to actually begin branching that glycogen. Because remember, branching actually increases the solubility of glycogen within the cytoplasm and it also increases the number of terminal positions on the glycogen.