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:
['7677', '4069', 'b', 'w', '4381', 'b', '5757', '711', '765', '8347', '6547', '9527', '945', '5333']

Ex Output:
b, w


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:
['3333', 't', 'u', 'w', '3829', '5689', '7267', '1363', '6113', '6767', '8441', 'u', 'o', 'c', '2667', 'n', 'z', '1467', '113', '2413', '5657', '1137', 'e', 'x', '6879', 't', 'r', '6423', 'y']

Ex Output:

c, e, n, o, r, t, u, w, x, y, z