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.

['r', 'q', '3649', 't', '3941', 'z', '3729', 's', 'g', '6905', 'h', 'v', '1085', '6353', 'a', '9395', '5433', 'a', '2565', 'p', 'a', 'h', '1491', 'j', 'b', 'v', 'e']
a, b, e, g, h, j, p, q, r, s, t, v, z

['8975', '7199']
-1

['u', '9243', '783', '5083', 'a', '9085', 'r', 'r', 'f', 'i', '3339', 't', '7645', 'n']

a, f, i, n, r, t, u