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