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