$ ./bpseq.py 1DDY_A.pdb
1 G 0
2 G 0
3 A 0
4 A 0
5 C 0
6 C 0
7 G 22
8 G 21
9 U 20
10 G 0
11 C 30
12 G 33
13 C 32
14 A 0
15 U 0
16 A 0
17 A 0
18 C 28
19 C 26
20 A 9
21 C 8
22 C 7
23 U 0
24 C 0
25 A 0
26 G 19
27 U 0
28 G 18
29 C 0
30 G 11
31 A 0
32 G 13
33 C 12
34 A 0
35 A 0