length	A	U	C	G
16	0	0	0	0
17	0	0	0	2
18	1	0	2	0
19	13	10	20	1
20	53	9	31	8
21	53	23	40	4
22	75	7	18	23
23	64	34	19	12
24	36	29	56	27
25	45	34	25	7
26	83	26	59	5
27	78	17	14	25
28	37	13	38	0
29	54	19	17	4
30	28	4	19	2
31	15	1	4	0
32	7	3	7	0
33	6	4	0	0
34	7	0	3	0
35	2	0	0	0
36	0	1	1	0
37	0	0	0	1
38	1	0	0	0
39	0	0	0	0
40	0	0	1	0
41	0	0	0	0
42	1	0	0	0
43	0	0	0	0
44	1	0	0	0
45	0	0	0	0
46	0	0	0	0
47	0	0	1	0
48	1	0	0	0
49	1	0	0	0
50	0	0	0	0