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