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