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:
['k', 'c', 'i']

Ex Output:
c, i, k


Ex Input:
['d', '1625']

Ex Output:
d


Ex Input:
['1081', '1179', 'y', 'm', '3019', '9963', 'o', 'w', 'h', 't', '6381', '1479', '731', '3301', '551', 't', '6643', '6449', '1229', '6245', 'w', 'o', 'f', 's', 'y', 'x']

Ex Output:

f, h, m, o, s, t, w, x, y