 Now, as I've mentioned in the past, this is any time I access any node. So what happens if instead of doing an insertion, I came in and I did a lookup on, I don't know, 50. So, just like a normal binary search tree, I would navigate sort of my tree, and once I saw 50, ah-ha-ha-ha, it needs to now become the new root. Well, we happen to go through those same rules. We see if it is a zig, a zig-zig, or a zig-zag. Again, zig-zig, or zig has no grandparent, and that's clearly not the case, because I see that I have an x, a y, and a z, so I have a grandparent. It's not a zig-zig because the relationship between the grandparent and parent, and the relationship between the parent and our kind of accessed node, are not the same. In this case, y is the right child of z, and x is the left child of y. So we know it's not this one, we know it's not this one, so that only leaves us with zig-zag. Now, if we are kind of going through those rules of what I do, since I've seen I got a zig-zag, that means I do my trinode restructuring, restructuring. And so, as always, we have to find out my a, my b, and my c. As always, once again that is in order, which means I look at my left child first, then I get to look at myself, and finally I get to look at my right child. So in our case, I need to access my left child first, but it's not being kind of classified if I'm looking at sort of only these three. I don't care about 25 right now, it's not in the three I'm dealing with. So if I skip over my left node in our trinode restructuring, that's fine. That means z happens to become my a. As always, I don't go immediately to y, because we see that y has a left child. As always, the in-order traversal is that I go to my left child, then I get to go to myself. So I see I've gone to myself, I went to my right child, I see that that right child has a left, so I go to that left child. I see I have no left child, so I get to go to myself, so b becomes x. There is no right child, so I can kind of come up the tree, and I see that, well, now that I'm done dealing with my left child or children, potential children, I can finally be myself. As always, once again, b is going to become the new parent with c and a being the children. So if we were to take this approach, we were to take that look up 50, what we should see happen here is that, again, my x becomes my new root, so 50 still for here. So what about my z? Well my z is going to become my new a, or my new left node, and my y is going to become my new right node. So what happens to sort of 25? Well, as we've said in the past, that's classified as t1, and we have seen in previous videos that t1 is going to become the left child of whatever a was. And so, now that we've done our look up on 50, we happen to notice that we are now set up in a, we've moved it to our root.