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:
['7367', '9757', '9431', 'h', 'a', 'k', '5833', '6237', 'g', '3585', '8665', 'g', '7517', '1561', 'p', 'p', '1307', '3325', 'q']

Ex Output:
a, g, h, k, p, q


Ex Input:
['h', 'b', '9601', 'h', 'h', 'h', '8099', '8265', 'i', 'd', '8791', 'p', '8059', '4309', '501', '2581', '9837', '157', '4785', '5925', 'q', '8491', '4779', 'r', 'l', 'k', '3679', 'v', 'g', 'g', '9731', '1909', '9783', 'f', '4293', '5009', 'o', '3057', '3157', 'c', '5587', 'b', 'f', 'd', 'k']

Ex Output:
b, c, d, f, g, h, i, k, l, o, p, q, r, v


Ex Input:
['b', '3983', 'k', 'c', '5969', 'm', '899', 's', 'b', '4981', 'e', '2557', '9453', '2307', '743', 'q', '4279', '4437', '5341', '425', 'b', '3371', '3939', '1769', 'm', '9713', 'e', '1217', 'y', 'c', 'd', 'v', '45', '4649', '2509', 'm', '1505', 'y', '2439', 'c']

Ex Output:

b, c, d, e, k, m, q, s, v, y