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:
['u', '635', '5249', '9457', 's', '9317', '9407', 'l', 'w', '9705', 'k', '429', '5489', 'e', 'd', '2457', 'o', '4665', '1675', 'l', 'y', 's', 'o', 't', '4285']

Ex Output:
d, e, k, l, o, s, t, u, w, y


Ex Input:
['331', '125', 'u', 'a', 's', '6995', 'i', '3613', '9727', '7087', 'l', 'b', '8291', '813', 'i', '1169', '2159', 'd', '1451', 'q']

Ex Output:
a, b, d, i, l, q, s, u


Ex Input:
['8315', 'b', '4333', 'f', '6507', '6211', '3475', 'c', 'e', '8039', '661']

Ex Output:

b, c, e, f