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