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:
['u', 'd', '4193', '5687', 'p', 'r', '7787', 't']

Ex Output:
d, p, r, t, u


Ex Input:
['h', 'l', 'i', '1507', 'h', '409', '6777', 'u', '5563', '6113', '6513', '9949', '461', 'z', 'm', '2519', 'r', '4699', 'n', 'x', '4645']

Ex Output:
h, i, l, m, n, r, u, x, z


Ex Input:
['k', 's', 'e', '4765', '4859', '2657', 'y', '2763', 'q', '2861', 's', 'u', 't', '4397', '4109', 'u', '6523', '3575', 'j', 'j', '3297', '7373', '3895', '7297', '3053', 'g', 'w', '1183', '269', 'e', '9115', '2799', '1123', '2919']

Ex Output:

e, g, j, k, q, s, t, u, w, y