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