Answer: 16

The values of k are that make it into the loop are 1, 2, 3, 4, 5, 6, 7, 8, 9. Statement r = r + r is done for k = 2, 4, 6 and 8, since it is only done when k is even. But statement r = r + r doubles r. If you start at 1 and double the number four times, you get 16.