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