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:
['p', '5229', '7521', 'y', 'n', 'u', 'c', '4047', '781', 'a', '4707', '7149', 'j', 'm', 't', '515', '7691', 'h', '4879', 'j', '6593', 'n', 'p', '2949', '1343', 'y', '2629', 'p', 'b', 'b', '2861', 'a']

Ex Output:
a, b, c, h, j, m, n, p, t, u, y


Ex Input:
['4861', 'r', '6391', '4647', '5193', 'p', '2797', '3015', 'l', '7583', '5619', 'i', '2075', 'q', '4711', 'd', 'i', '4641', 'n', 'w', 't', '4329', '1227']

Ex Output:

d, i, l, n, p, q, r, t, w