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:
['7965', '6465', 'c', '7963', 'j', '6839', '9989', '1019', 'x', '1303', '2633', 'y', '6865', 'a', 'k', '635', '3719', '7229', 'k', 't', 'r', '5741', '9569', '4931', '1125', 'f', '5429', 'c', '2065', '6315', 'e', '6877', '2005', 'x', '7831', '7297', 'm', '3571', 'b', '8617', '2981', 'i', '5105', 'g', 'u']

Ex Output:
a, b, c, e, f, g, i, j, k, m, r, t, u, x, y


Ex Input:
['8975', '7199']

Ex Output:
-1


Ex Input:
['2267', '3121', '8189', 'j', 'h', '9455', '4181', 'o', 'h', '2605', '2491', 'n', '9657', '6057', 'e', 't', '8725']

Ex Output:

e, h, j, n, o, t