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