And finally, if we add these charges up, we'll see that our charge, the net charge in this particular case, is zero. And so this can basically be used to find what the actual pi value of this protein is. And we'll do that in just a moment. So actually, let's add E, where in E we want to find the pi, okay? And in D, so we follow these same procedures we basically have in the beginning, because our PH is eleven. Now, this will have lost the H atom.