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:
['x', 'i', 'r', '6011', 't', 'f', 'b', 'i', '8367', '4051', '1459', 'f', '5583', '9609', 'l', 'q', 'g', '8443', 'o', '8697', '7053', '8325', 'k', '7021', 'q', 'm', '6899', '9981', '8985', 'i', 'j', '8043', 'k', '535', '7603', '7629', 'k', '2779', 'g', '2049', 'x', 'd', '8527', 'k', 'q']

Ex Output:
b, d, f, g, i, j, k, l, m, o, q, r, t, x


Ex Input:
['6411', 'x', 'i', '267', 'z', 'e', '5483', '8033', '3697', 'z', '4167', 'e', 'f', '7229', 'i', 't', '2197', 'g']

Ex Output:
e, f, g, i, t, x, z


Ex Input:
['l', 'n', 'q', 'c', 'q', 's', 'k', 'p', 's', 'q', 'c', 'a', '1511', '1977', '5735', '8771', 'n', '7763', '9733', '3649', 'r', '8817', '2781', '2627', 'a', '7945']

Ex Output:

a, c, k, l, n, p, q, r, s