14
0 1 4 5
0 0 3 4
0 0 0 1
3 0 3 4
3 1 2 5
3 0 1 2
6 1 4 5
6 0 2 4
0 0 1 2
9 1 4 5
9 0 2 3
11 0 3 4
11 1 2 5