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