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:
['o', 'z', 'h', '3965', 'n', '3009', '173', '997', '3987', '5799', '2331', 'p', 'x', '897', '8213', '451', 'u', 't', 't', '9917', '4501', 't', 'c', 'i', 'w', 'w', 'u', '2977', 't', 'b', '4161', '9281', 'w', 'f', '3137', '5745', 'e', '673', '6363', 'h', 'q', 'x', 'm', '9505']

Ex Output:
b, c, e, f, h, i, m, n, o, p, q, t, u, w, x, z


Ex Input:
['7147', 'd', 'y', 'y', 'n', 's', '4763', 'j', 'b', 's', '4039', '9151', '6763', 'w', 'g', 'k', 'j', 'x', 'h', 'm', '3805', 'i', '5393', 'n', 'w', 'a', '1121', 'i', 'e', '4877', '3407', 'i', 'm', '3389', '3983', 'f', '8075', 'g', '6641', '17']

Ex Output:

a, b, d, e, f, g, h, i, j, k, m, n, s, w, x, y