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:
['l', '6313', '3199', 'w', '249', '8747', '7391', '3871', '173', 'x', 'o', '8647', '4413', '3645', '6123', '701', 'q', '2147', '4289', '7333', '533']

Ex Output:
l, o, q, w, x


Ex Input:
['8381', 'j', '761', '5431', '7601', 'd', '4339', '1479', 'b', 'x', 'f', 'w', '2437', '7725', '6385', '411', 'w', 'w', 'i', '2769', '5709', '5703', 'k', '5301', '6503', '7833', 'y', '3813', '7061', '5531', 'n', '2251', 'y', '8941', '8481', 's', 't', 't', '3345', 'k', '1545']

Ex Output:
b, d, f, i, j, k, n, s, t, w, x, y


Ex Input:
['s', '3501', 'v', '4283', 'd', '4215', '2491', 'o', '577', 'o', '1821', 'w', 'r', '981', 'u', '9837', '1513', 'e', '2731', '1041', 'w', '5937', 'x', 'f', 'r', '9955', '9695', '7989', 's', '9425', 'g', '7853', 'f', 'h', '4363', 's', '8189', '8217']

Ex Output:

d, e, f, g, h, o, r, s, u, v, w, x