9 3
0 0 1 2
0 0 2 1
0 0 3 2
0 0 3 3
0 1 4 2
0 1 4 3
0 1 5 3
0 1 6 1
0 1 6 3
0 1 7 1
0 2 4 2
0 2 5 2
0 2 5 3
0 2 6 1
0 2 7 1
0 2 7 3
0 3 4 2
0 3 5 1
0 3 5 2
0 3 7 1
4 4 5 5
4 4 6 5
4 4 7 5
4 6 6 5
4 7 7 6
5 5 6 7
6 6 7 7