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.

['5075', '9169', '4659', '7605']
-1

['s', 's', '3619', '6051', 'h', '213', '3937', 'v', 'p', 'y', '8449', '9337', '5327', 'a', 'a', 'w', '3985', 'n', 'm']
a, h, m, n, p, s, v, w, y

['s', 't', '7935', '691', 'd', 'z', '3277', 'i', 'q', '7669', 'b', '4973', 'h', '4853', '2687', 's', 'q', '9311', 'q']

b, d, h, i, q, s, t, z