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:
['7799', '8163', '3389', 'x', 'k', 'm', '6085', 'f', '1131']

Ex Output:
f, k, m, x


Ex Input:
['s', 'w', 'c', '4137', 't', '2437', '349', 'h', '4539', 't', 'b', 'y', 'q', 't', '9087', 'c', '9489', '6285', '6247', '8353', 'n', 't', '8661', 'p', 'z', 'p', '773', 'w', 'q', '8081', 'r', 'u', 'z', 'k', 'a', 'b', '7513', '5549', '5325', '1101', 's', '6507', '3317']

Ex Output:
a, b, c, h, k, n, p, q, r, s, t, u, w, y, z


Ex Input:
['j', 'x', 'b', 'u', 'k', 't', '2683', 'e', '1923', '6929', '487', 'w', 'r', 'e', '1691', 'l', '7923', 'r', 'a', 'z', '9963', 'l', '4367', '6767', '4723', 'z', 'd', '7919', 'x', 'y', 'b', '7431', 'a', '2491', '2797', '5365', 'o', 'g', '4151', '1483', '6961', 'g', '3751']

Ex Output:

a, b, d, e, g, j, k, l, o, r, t, u, w, x, y, z