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