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