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