7
 0  0  0  0  0  0  0
 0  0  0  0  0  0  0
 0  0 -1 -1 -1  0 +1
 0  0 -1 +1 +1 +1 +1
 0  0  0 -1  0  0 +1
 0  0  0  0  0  0 +1
 0  0  0 -1  0  0 -1