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