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:
['x', 'j', '9747', 'i', '2015', '3505', 'q', 'n', 'h', '3011', 'u', '8043', 'j', 'f', 'd', 'a', 'p', '5817', 'l', 'q', '2275', 'n', '7085', '5373', 'l', 'g', 'b', '8043', '3085']

Ex Output:
a, b, d, f, g, h, i, j, l, n, p, q, u, x


Ex Input:
['5075', '9169', '4659', '7605']

Ex Output:
-1


Ex Input:
['h', '8857', 'p', '9725', 'd', '47']

Ex Output:

d, h, p