4 5
0 1 0 0 -1
0 0 1 0 1
0 0 0 1 -3
1 0 0 0 1

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

1 5
0 0 1 0 1