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