9
1 5,7,9,10,12,14,
2 4,9,10,11,15,
3 2,4,9,10,
4 1,3,5,7,8,18,
5 2,3,4,5,6,7,8,9,10,11,14,16,17,18,
6 5,6,7,8,9,10,13,16,
7 5,6,7,8,9,10,14,17,
8 5,6,7,8,9,10,11,14,15,17,
9 1,3,5,6,7,8,9,10,13,16,18,