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:
['5737', 'b', 'e', 't', '7419', 'n', 'y', '5225', '6485', 'b', '1343']

Ex Output:
b, e, n, t, y


Ex Input:
['4371', '9499', 'e', 'w', '9969', '8367', '2897', '1745', 'i', '7049', '9773', 'h', '9649', 'u', '4673', '8513', '8547', 'z', '1995', '7739', '2215', '171', 'c', '7527', '2479', 't', '5223', 'p', '2313', '3243', '2281', 'r', 'c']

Ex Output:
c, e, h, i, p, r, t, u, w, z


Ex Input:
['u', 'c', 't', '6245', 'r', '3055', '7551', 'b', 't', '2551', '6443', '17', 'a', 'p', '2955', 'r', '2949', 'y', '3155', 'z', '271', '1709', '3155', 'l', '2835', 'y', '1131', '5']

Ex Output:

a, b, c, l, p, r, t, u, y, z