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