13
0 1 | 0 2
0 1 | 2 0
0 1 | 2 1
0 1 | 2 2
0 2 | 2 0
0 2 | 2 1
0 2 | 2 2
0 3 | 2 0
0 3 | 2 1
0 3 | 2 2
0 4 | 2 0
0 4 | 2 1
0 4 | 2 2