p cnf 9 13
-1 2 0
-1 3 0
-2 -3 4 0
-4 5 0
-4 6 0
-5 -6 7 0
-7 1 0
1 4 7 8 0
-1 -4 -7 -8 0
1 4 7 9 0
-1 -4 -7 -9 0
8 9 0
-8 -9 0