10
2 2
-1 2
1 3 
2 2
1 1
1 -1
2 2
-2 -1
0 1
2 2
2 -2
-2 1
2 2
1 1
-1 -1
2 2
-1 2
-2 1
2 2
1 -1
0 -2
2 2
2 0
-1 2
2 2
-2 2
1 -1
2 2
2 2
-2 -1