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