11
0 -1 -4 -1
2 5 2 1
-1 -2 3 2
-1 5 -1 1
1 -1 5 -1
-2 2 2 -2
-1 -4 -1 0
2 0 2 -4
-2 0 2 0
-4 2 0 2
3 -1-1 3