4 4
0 0 0
0 1 1
0 2 1
0 3 0

1 0 1
1 1 2
1 2 2
1 3 1

2 0 1
2 1 2
2 2 2
2 3 1

3 0 0
3 1 1
3 2 1
3 3 0

