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', '8917', '3773', '6723', 'r', 'z', '3265', 'o', 'f', 'q', '9343', 'f', '1925', 'u', 'b', 'o', '5275', 'b', 'n', 'd', 'j', '4825']

Ex Output:
b, d, f, j, k, n, o, q, r, u, z


Ex Input:
['3411', 'a', 'v', 'j', '8925', '909', 'h', 'l', 'r', '1371', 'u', '7789', '4813', 'u', 'q', 'i', '8473', 'n', '7191', 'c', '4641', 'e', '5107', 'q', 'z', 't', '105', 'q']

Ex Output:
a, c, e, h, i, j, l, n, q, r, t, u, v, z


Ex Input:
['7241', '4629', 't', '5361', '947', '8251', 'r', '19', '2901', 'i', '1973', '2699', 'a', 'k']

Ex Output:

a, i, k, r, t