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