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