1b
a
2d
3a
4c
5b
a
6b
7c
8c
9b
a
10a
a
11b
12a
13b
14b
15a
16d
17b
18c
d
19d
20d
21c
22d
23a
24b
a
25a
b
26b
27c
28a
29b
30a
a