A B C D E F
1  X A X A A A
2  X A A X X X
3  A X X X A X
4  X A X A A A
5  X A X A A A
6  A X X X A X
7  X A A X X X
8  X A X A A A
9  X A A X X X
10 X A X A A A
11 A X X X A X
12 A A A X A A
13 A A A X A A
14 A A A X A A
15 A A X A A A
16 A A A A A A
17 A A A A A A
18 X A X A A A
19 A A A A A A
20 A A A A A A
21 A A A A A A
22 A A A A A A
23 A A A A A A
24 A A A A A A
25 A A A A A A
26 A A A A A A