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:
['c', '1693', 'l', 'u', 'x', '3609', 'h', '4159']

Ex Output:
c, h, l, u, x


Ex Input:
['895', '2049', '8839', '1773', 'v', '467']

Ex Output:
v


Ex Input:
['343', '569', '319', 'e', '9111', '3295', 'r']

Ex Output:

e, r