length	A	U	C	G
16	0	0	0	0
17	0	0	0	0
18	0	1	1	2
19	6	2	2	4
20	16	1	5	4
21	15	1	4	11
22	5	6	6	12
23	11	3	1	10
24	10	3	5	13
25	3	4	7	12
26	9	4	1	3
27	3	1	1	5
28	3	3	4	3
29	6	3	0	0
30	1	1	0	1
31	2	1	0	1
32	0	1	0	1
33	0	0	0	0
34	0	0	0	0
35	0	0	0	0
36	0	0	0	0
37	0	0	0	0
38	0	0	0	0
39	0	0	0	0
40	0	0	0	0
41	0	0	0	0
42	0	0	0	0
43	0	0	0	0
44	0	0	1	0
45	0	0	0	0
46	0	0	0	0
47	0	0	0	0
48	0	0	0	0
49	0	0	0	0
50	0	0	0	0