14
0 1 0 1
2 0 2 0
0 -3 0 -3
-4 0 -4 0
0 5 1 5
-1 6 0 6
-7 0 -7 1
-8 -1 -8 0
-1 9 1 9
-1 -10 1 -10
11 -1 11 1
-12 -1 -12 1
13 -1 13 2
-2 -14 1 -14
15
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15