data co3; input y s a b; cards; 7 1 1 1 14 1 2 2 12 1 3 3 3 2 1 1 5 2 3 2 11 2 2 3 6 3 3 1 7 3 1 2 11 3 2 3 12 4 2 1 13 4 3 2 9 4 1 3 7 5 2 1 9 5 1 2 8 5 3 3 8 6 3 1 13 6 2 2 9 6 1 3 ; run;