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:
['9483', '501', 'j', 'k', '3103']

Ex Output:
j, k


Ex Input:
['2705', 'n', 'r', '8259', '6839', '3239', 'w', 'z', '2611', '2957', '2303', '6315', '7801', 'c', 'w', 'm', '5049', '6465', '599', 'h', 'q', '7559', 'n', '9917', 'v', 'l', '643', '6415', '3587', 'c', '917', '4435', 'p', 'a', '317']

Ex Output:
a, c, h, l, m, n, p, q, r, v, w, z


Ex Input:
['t', 'r', '2959', '2517', 'a', '9959', '729', '511', 'y', 'r', '465', 'c', '687', 'm', 'b', 'm', '3449', '9713', 'g', '8275', '8823', 'a', 'z', 'w', '2185', '6283', '8457', '8137', '7163', '8329']

Ex Output:

a, b, c, g, m, r, t, w, y, z