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