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