You could just say, hey look, four choose two, or the number of combinations of selecting two from a group of four. This is going to be four factorial over two factorial times four minus two. Four minus two factorial. And I'm going to make this color different just so you can keep track of how I'm at least applying this. And so what is this going to be? This is going to be four times three times two times one over two times one times this right over here is two times one. So that will cancel with that.