1-1 1-2 2-1 2-2 3-1 3-2 4-1 4-2 5-1 5-2 6-1 6-2 7-1 7-2 8-1 8-2 9-1 9-2 10-1 10-2 11-1 11-2 12-1 12-2 13-1 13-2