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