That's 6 factorial over 4 factorial times 6 minus 4 factorial, so that's 2 factorial. And that's times 1 half to the 6th. And I'll switch colors again, just to stop the monotony. And that equals, let's see, 6 times 5 times 4 times 3 times 2, we don't have to write the 1 times 1, I'll do it anyway. Over 4 factorial, 4 times 3 times 2 times 1, and then 2 factorial, 2 times 1. So that cancels with that. The 1 we can ignore.