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