length	A	U	C	G
16	0	0	0	0
17	2	0	0	1
18	4	1	2	0
19	15	0	14	0
20	27	5	15	9
21	51	10	18	19
22	48	15	12	5
23	28	7	16	7
24	19	9	4	5
25	13	2	4	0
26	12	0	4	3
27	1	1	2	2
28	3	0	1	1
29	1	0	0	0
30	1	0	0	1
31	1	0	0	0
32	1	1	0	0
33	0	0	1	0
34	1	0	0	0
35	0	0	0	0
36	1	0	0	0
37	0	0	0	0
38	1	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	1	0	0
44	0	0	0	0
45	2	0	0	0
46	1	0	0	0
47	0	0	0	0
48	0	0	0	0
49	0	0	0	0
50	0	0	0	0