18 16
2-1 -1 -1 -1  1  1  1  1  0  0  0  0  0  0  0  0
3-1  0  0  1 -1  0  1  0 -1  1  0  0  0  0  0  0
4 0  1  1  2 -1 -1  0  0 -1  0 -1  0  0  0  0  0
5 0  0  0  0  0  1  1  0 -1  0  0 -1  0  0  0  0
6 0  1  1  1 -1  0  0  0 -1  0  0  0 -1  0  0  0
7 0  0  1  2 -1 -1  1  0 -1  0  0  0  0 -1  0  0
8-1  0  1  1 -1 -1  1  0 -1  0  0  0  0  0  1  0
9 0  0  0  1 -1  0  0  0 -1  0  0  0  0  0  0  1
10