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:
['f', '9203', 'w', 'f', '3751', '8095', '1319', 'f', '3017', 'r', 'y', '8221', '2715', '9959']

Ex Output:
f, r, w, y


Ex Input:
['i', 'y', '8339', 'd', 'b', '7471', '6577', '9037', '4503', '6287', '1439', '8863', '9201', '2661', 'x', 'l', 'v', 'w', 'a', 'f', '8885', '519', '7631', 'g', '7203', '8605', '2429', '9165']

Ex Output:
a, b, d, f, g, i, l, v, w, x, y


Ex Input:
['l', 'm']

Ex Output:

l, m