length	A	U	C	G
16	0	0	0	1
17	0	0	0	0
18	0	0	0	2
19	5	0	0	3
20	18	1	0	2
21	28	9	1	7
22	28	1	3	10
23	22	0	0	0
24	11	1	0	2
25	13	0	1	0
26	17	2	1	1
27	9	0	3	0
28	4	0	0	4
29	3	0	0	0
30	4	1	0	0
31	1	0	0	0
32	1	0	0	0
33	4	1	0	0
34	0	0	0	0
35	0	0	0	0
36	2	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	1	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