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