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:
['1653', '3177', 'b', '2785', '2515', 'd', '5513', '5599', '2947', 'v', '2771', '5697', '2913', '4161', '5939', '2655', '6787', '9851', 'q', '3199', 'x', '1305', '9423', '9117', '4821', 'j', '7963', 'i', 's', '469', 'r', 'w']

Ex Output:
b, d, i, j, q, r, s, v, w, x


Ex Input:
['g', '8591', '4463', '2189', '7901', '1457', 'f', 'i', '9031', 'r', '5519', '3955', 'd', '2093', 'c', 'y', '6591', '6463', 'h', '4371', '111', 'p', '3221', '4185', 'p', '8761', 'w', 'p']

Ex Output:
c, d, f, g, h, i, p, r, w, y


Ex Input:
['r', '6417', '4145', '6233']

Ex Output:

r