In this task, you are given an input list A comprising of numbers and alphabets. You need to extract and sort the unique alphabets in the list. The alphabets in the input list will only be in lowercase. Return -1 if there is no alphabet in the input list.

Ex Input:
['9117', '1153', 'f', 'b', '9979']

Ex Output:
b, f


Ex Input:
['2409', 'q', 'w', 'e', 'x', '4737', 'w']

Ex Output:
e, q, w, x


Ex Input:
['4651', 'w', 'z', 'h', 'w', 'j', 'r', 'j', '6577', '1635', 'e', 'c', '3189', 'j', '7331', 'd', 's', 's', '3643']

Ex Output:

c, d, e, h, j, r, s, w, z