25
-10 20
20 20
30 0
10 20
20 -20
0 20
10 -30
-10 -30
10 10
-10 10
-10 -10
0 -10
0 0
1 1
2 2
3 3
4 4
5 5
-10 30
6 6
7 7
-20 -20
10 30
-30 0
-20 20