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