1 -> 3
1 -> 9

2 -> 2
2 -> 4
2 -> 8
2 -> 10

3 -> 1
3 -> 5
3 -> 7
3 -> 11

4 -> 1
4 -> 6
4 -> 11

5 -> 2
5 -> 10

6 -> 3
6 -> 9

7 -> 4
7 -> 8

8 -> 5
8 -> 7

9 -> 6