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