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:
['p', 'p', '7899', 'u', '971', '7289', 't', '5217', 'k', 'z', 'y', 'y', '6905', '9499', '4085', 'x', '955', 'v', 'j', '9049', '7927', '1757', '193', '2181']

Ex Output:
j, k, p, t, u, v, x, y, z


Ex Input:
['8879', 'x', '1383', '4925', '2867', 'j', 't', 'e', 'w', 'p', 't', 'w', 'l', '7447', '1877', '7747', 'k', 'b', 'x', '8565', 'q', '8575', '5711', '2949', '5637', '2197', '4905']

Ex Output:
b, e, j, k, l, p, q, t, w, x


Ex Input:
['j', '3861', 'a', 'k', 'e', 'n', '6779', 'q', 'r', '3433', '2589', '3067', 'v', '7167', '4151', 'f', 'h', '5747', '7509', 's', '9673', '7305', '7745', 'a', 'o', '207', '5435', 'z', '2689', '4249', '3131', 'u', '2039', '3973', 'p', 'w', '6387', '2673', '5973', '9307', '8887', 'b', '9415', 'k', 'y']

Ex Output:

a, b, e, f, h, j, k, n, o, p, q, r, s, u, v, w, y, z