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