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