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:
['l', 'i']

Ex Output:
i, l


Ex Input:
['2349', 'p', 'a', '435', 'y', 'h', '3249', 'o']

Ex Output:
a, h, o, p, y


Ex Input:
['i', 's', 'x', 'k', '541', '239', '2807', 'f', '9783', '8569', '1823', '9377', 'o', 'i', 'o', '1365', '5547', '8161', '8585', 'q', 't']

Ex Output:

f, i, k, o, q, s, t, x