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