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:
['2329', 'i']

Ex Output:
i


Ex Input:
['z', 'l', '1759', 'k', '8197', 'v', '931', '2587', '7219', '3455', 'e', '8135', 'm', 'n', 'm']

Ex Output:
e, k, l, m, n, v, z


Ex Input:
['6723', 'l', 'q', '3005', 'w', '4275', 'f', 'p', '5099', 'x', 'r', 'u', 'u', '3201', '675', '8877', '4437', 'v', 'w', 'y', '9337', '1359', 'j', '8851', '8253', '9903', '1161', 'e', 'u', 'y', 'u', '225', '7165', 'f', '5135', '7383', 'z', 'x', '249', '5297', 'e', 'x', 'g', 'm', '7731']

Ex Output:

e, f, g, j, l, m, p, q, r, u, v, w, x, y, z