1/1, 1/2, 10/1, 10/2, 11, 12/1, 12/2, 13, 14, 15, 16, 17, 18, 19, 2, 20, 3, 4/1, 4/2, 5, 6/1, 6/2, 7, 8/1, 8/2, 9/1, 9/2