So this is a two and this is a three. And so we have one, two, three and four. Now, to determine whether it's the R or the S absolute configuration, we basically have to take this molecule oriented in such a way so that the fourth group, H, points into the board so that we can't actually see it. So after we oriented like so we get this age group points into the board, and these three groups will point out as shown in the following diagram. So we basically rotate it slightly so that these two are coming out of the board. This is coming out of the board, and this group will point into the board.