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:
['6209', 'x', 'j', 'w', '7965', '4905', '6297', '4291', '7183', 'a', 'l', '5267', 'r', '5935', 'a', '7865', 'h', 'p', '6117', 'a', 'y', 'y', 't', 'v', '7271', 'e', 'e', 'z', 'i', 'l', '4731', '2059', 'm', '5703', 'k', 'f', '8125', 'e', '7569', 'r', '2287', '593']

Ex Output:
a, e, f, h, i, j, k, l, m, p, r, t, v, w, x, y, z


Ex Input:
['4857', 'z', '313', '7813', '9935', 'o', 'w', 'i', 'x', 'o', 'e', 's', 'a', 'p', 'i', 'v', 'x', '6743', 'p', '435', 'u', 'a', 'h', '607', '2491', '6159', 'u', '7761', '6197', '3449', '3459', 'e', 'g', '8731', '335', '2883', '3941', 'n', '1881', 'y', 'j', '8189', 'k', '7593', '2747']

Ex Output:
a, e, g, h, i, j, k, n, o, p, s, u, v, w, x, y, z


Ex Input:
['w', '1781', 'c', '561', 'f', '3077', 'u', 'n', '8423', '2671', '4713', 'i', '6423', 'l', 'g', 'a', '9973', 'z', 'o', 'm', 'd', 'a', 'j', 'x', 'y', 'j', '8613', 'n', 's', 'q', 'j', 'q', '5999', 'o', 'd', '299', '3679', 'a']

Ex Output:

a, c, d, f, g, i, j, l, m, n, o, q, s, u, w, x, y, z