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