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:
['r', 'y', 'c', '3211', '9245', '8459', '8521', '5781', 'w', 's', 'd', '5299', 'a', 'y', 'g', 'm', '6435', '8605', 'e', 'h', '6871', 's', '387', 'l', '5829', 'e', 'd', '9545', '2945', 'k', 'v', 't', '8449', '2199', 'm', '2599', '1489', '6623', 'x', 'l']

Ex Output:
a, c, d, e, g, h, k, l, m, r, s, t, v, w, x, y


Ex Input:
['a', 'a', 'b']

Ex Output:
a, b


Ex Input:
['7279', '3103', '3387', '205', '8205', '1589', '9541', '7991', 'm', 'n', '2433', 'w', 'x', 'h', '833', '835', 'y', 'o', 'j', '679', 'q', 'i', '3571', '2123', '9049', 'x', 'o', '9987', 'x', '3359', 'r', '197', '207', 'y', 'y', '5953', '6833', '8357', 'x', '5785', '435', 'l', '8049', '2769']

Ex Output:

h, i, j, l, m, n, o, q, r, w, x, y