length	A	U	C	G
16	1	0	0	0
17	0	0	1	1
18	6	0	4	0
19	14	7	8	8
20	16	4	3	13
21	24	5	12	9
22	17	8	3	10
23	30	6	7	14
24	12	4	8	9
25	8	2	0	4
26	11	4	2	4
27	6	0	2	2
28	1	0	0	0
29	0	0	0	0
30	0	0	0	0
31	0	0	0	0
32	0	0	0	0
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	0	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