4 4
0 -2 -7  0
9  2 -6  2
-4  1 -4  1
-1  8  0 -2
4 3
0 -2 -7
9  2 -6
-4  1 -4
-1  8  0 
2 2
-1 -1
-1 -1
3 3
1 1 1
1 1 1
1 1 1
3 3
1 1 1
1 -9 1
1 1 1
