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:
['h', 'l', 'i', '1507', 'h', '409', '6777', 'u', '5563', '6113', '6513', '9949', '461', 'z', 'm', '2519', 'r', '4699', 'n', 'x', '4645']

Ex Output:
h, i, l, m, n, r, u, x, z


Ex Input:
['9947', '3353', '8643', '4621', '4857', 'y', '7075', 'c', '8911']

Ex Output:
c, y


Ex Input:
['x', 'p']

Ex Output:

p, x