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:
['s', '2507', '3091', 'g', '7643', '2573', 'w', 'r', '1977', 'q', 'c', 'j', '1335', '9671', '7317', '567', '2041', '5777', 'w', 'm']

Ex Output:
c, g, j, m, q, r, s, w


Ex Input:
['i', 'i', 'h', 'g', '5123', 'i', 'r', '3183', 'w', 'g', 's', '9777', '455', 'l', 'r', 'h', 'e', 's', 'v', '6823', '463', '9603', 'e', '947', '7071', 'c', '3373', 'j', 'w', 'm', 's', 's', '3483', '9567']

Ex Output:
c, e, g, h, i, j, l, m, r, s, v, w


Ex Input:
['e', '6655']

Ex Output:

e