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