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.

['k', 'c', 'i']
c, i, k

['5433', '4011', '2113', '2299', 'e', '9829', 'd', 'q', 'e', '3921', 'a', 'q', '8953', 'q', 'g', 'w', 'z', 'u', '4425', 'b', 'q', '5315', 'b', 'u', 'h', 'y', '9733', 'b', 'c', '1225', 'a']
a, b, c, d, e, g, h, q, u, w, y, z

['k', 'c', '45', '445', '8615', '2835', 'x', 'f', 'n', 'y', 'y', '3181', '8731', 'a', 'w', 'e', 'g', 'w']

a, c, e, f, g, k, n, w, x, y