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:
['u', 'o', 'b', 'b', '5873', 'w', 'v', '4171', '7957', '3501', '2563', 'l', 'q']

Ex Output:
b, l, o, q, u, v, w


Ex Input:
['d', '1989', '6365', 'y', 'm', '1245', '7539', 'm', '3787', '6987', 'e', 'e', 'y', '9577', 'b', '5', '8179', 'x', '2853', '6337', 'w', 'f', 'b', 'q', '563', '6077', '1133', 'x', '6045']

Ex Output:
b, d, e, f, m, q, w, x, y


Ex Input:
['631', 'e', 't', '9643', 'g', 'x', '4705', 'b', 'o', 'p', 'b', 'o', 'p', '4977', 'r', '627', 'b', 'y', '8517', '7183', '5633', 'a', 'r', 'o', '4053', 'j', 'e', '4833', '6341', '1737', 'm', 'd', 'i', 'o', 'm', '1129', 'e', '2397', '4999', 'w', '2077', 'q', '8137']

Ex Output:

a, b, d, e, g, i, j, m, o, p, q, r, t, w, x, y