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.

['7599', '1593', 'y', '5323', 'i', '2811', '3271', 'p', '9913', 'd', 's', 'h', '3147', 'x', 'b', '3635', '379', 'j', '5531', '3789', '1273', 'c', '9725', '5361', '8409', 'm', '989', '7933', '8077', '1565', '705', 'n', 'w', 'w', 'f', 'g', '6503', '1895', 'q', 'w', 'b', 'i', '4173', 'i', '2847']
b, c, d, f, g, h, i, j, m, n, p, q, s, w, x, y