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:
['i', 'x', 'n', 'w', '8915', 'd', 'd', 'd', '6025', '7861']

Ex Output:
d, i, n, w, x


Ex Input:
['9783', '3185', '8225', 'u', '1123', 'd', '3453', 'i', '7713', '8457', '8609', 'h', '2767', 'e', '7191', '2929', '1089', '393', 'e', 'd', '11', '9329', '683', '1271']

Ex Output:
d, e, h, i, u


Ex Input:
['b', '7333', 'q', 'q', '7187', 'w', 'b', '6803', 'p', 'u', 's', 'q', '7495', '1045', '901', '9703', 's', 'y', 'n', 'u', 'm', '8971', 'a', 'c', 'p', '1755', '6151', '9351', 'o', 'y', 'i', 'v', 'y']

Ex Output:

a, b, c, i, m, n, o, p, q, s, u, v, w, y