c GRASP-paper working example
p cnf 18 13
-1 2 0
-1 3 9 0
-2 -3 4 0
-4 5 10 0
-4 6 11 0
-5 -6 0
1 7 -12 0
1 8 0
-7 -8 -13 0
-12 13 0
10 -11 0
14 15 16 0
17 18 0