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:
['331', '125', 'u', 'a', 's', '6995', 'i', '3613', '9727', '7087', 'l', 'b', '8291', '813', 'i', '1169', '2159', 'd', '1451', 'q']

Ex Output:
a, b, d, i, l, q, s, u


Ex Input:
['p', 'f', 'h', '1977', '6221', 'i', 'a', 'l', '5225', '8059', 'c', 'w']

Ex Output:
a, c, f, h, i, l, p, w


Ex Input:
['6077', '3307', '781', 'k', 'k', 'h', '2927', 'v', '1379', 'u', 'h', '287', 'r', '6227', '8193', 'w']

Ex Output:

h, k, r, u, v, w