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