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