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:
['2409', 'q', 'w', 'e', 'x', '4737', 'w']

Ex Output:
e, q, w, x


Ex Input:
['w', '5341', 'b', '6243', 'v', '877', '1087', '6763', '5241', '3369', '9119', 't', 'v', 'j', '8261', 'o', 'b']

Ex Output:
b, j, o, t, v, w


Ex Input:
['r', 'e', '35', '2105', '6715', 'o', 'a', 'n', 'p', '5097', 'x', 'f', '8519', 'b', '7153', 'r', 'b', '4169', '8923', 'm', '587', 'o', '9005', '6715', '2497', '9973', 'q', 'u', '7833', 'y', '7171', 's', '1335', '1349']

Ex Output:

a, b, e, f, m, n, o, p, q, r, s, u, x, y