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