0 -> 0
1 -> 0, 1, 4, 5
2 -> 2
3 -> 0, 1, 2, 3, 4, 5
4 -> 4
5 -> 4, 5
6 -> 4, 5, 6
7 -> 0, 1, 2, 3, 4, 5, 7
8 -> 0, 1, 2, 3, 4, 5, 7, 8, 9
9 -> 0, 1, 4, 5, 9
10 -> 0, 1, 2, 3, 4, 5, 10