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

Ex Output:
c, y


Ex Input:
['2293', 'p', '9787', '7241', '8689', 'u', '3141', 'h', 'c', 'b', 'f', 's', '319', 'c', 'p', '6909', 'p', 'f', '1717', 'd', '2285', 's']

Ex Output:
b, c, d, f, h, p, s, u


Ex Input:
['6047', 'o', 'm', 'a', '6557', '8121', 'f', 'q', 'h', 'o', '7999', 'e', 'f', 's', 'f', '1735', 'b', '8457', '9071', '4097', '8621', '3163', 'h', '8095', '8881', 'x', 'w', 'd', 'j', '1973', '8905', 'w', '8501', 'r', '7215', '1353']

Ex Output:

a, b, d, e, f, h, j, m, o, q, r, s, w, x