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