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