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