20
17 20 19 16 11 12 15 13 14 18 
15 18 16 20 19 13 14 11 12 17 
15 11 16 20 17 12 18 19 14 13 
17 14 19 11 15 12 18 16 20 13 
14 11 17 15 13 19 16 12 20 18 
20 19 11 13 16 14 15 18 17 12 
18 13 15 19 11 20 14 17 12 16 
17 20 12 14 15 13 11 18 19 16 
13 20 18 19 16 15 14 12 11 17 
18 16 11 19 20 13 14 17 12 15 
6 1 4 8 10 9 5 3 2 7 
9 2 5 3 4 8 10 1 6 7 
3 5 1 8 4 2 6 9 7 10 
5 10 7 2 9 3 1 6 8 4 
7 10 4 6 2 1 3 8 9 5 
8 1 10 7 6 5 9 3 2 4 
5 9 4 7 8 1 10 2 6 3 
3 6 9 5 8 1 4 2 7 10 
6 7 8 2 5 9 10 1 3 4 
5 3 7 2 10 8 1 6 4 9 
forbidden 1 13
forbidden 1 18
forbidden 2 12
forbidden 2 16
forbidden 2 19
forbidden 2 20
forbidden 3 11
forbidden 3 13
forbidden 3 15
forbidden 3 19
forbidden 3 20
forbidden 5 12
forbidden 5 17
forbidden 5 19
forbidden 7 16
forbidden 8 13
forbidden 8 15
forbidden 8 16
forbidden 8 17
forbidden 8 19
forbidden 9 11
forbidden 9 12
forbidden 9 20
forbidden 10 11
forbidden 10 12
forbidden 10 14
forbidden 10 17
forbidden 10 18
forbidden 10 19
forbidden 10 20