What is the rhyme scheme for an acrostic poem?

line: rhyme scheme:

1 a

2 b

3 a

4 b

5 c

6 b

7 c

8 b

9 d

10 b

11 d

12 b

13 e

14 f

15 e

16 f

17 g

18 h

19 g

20 h

21 i

22 j

23 i

24 j

25 k

26 l

27 k

28 b

29 m

30 m

31 b