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