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