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.

Example Input: ['7965', '6465', 'c', '7963', 'j', '6839', '9989', '1019', 'x', '1303', '2633', 'y', '6865', 'a', 'k', '635', '3719', '7229', 'k', 't', 'r', '5741', '9569', '4931', '1125', 'f', '5429', 'c', '2065', '6315', 'e', '6877', '2005', 'x', '7831', '7297', 'm', '3571', 'b', '8617', '2981', 'i', '5105', 'g', 'u']
Example Output: a, b, c, e, f, g, i, j, k, m, r, t, u, x, y

Example Input: ['8829', 'm', '5369', 'q', '5737', '7799', '5705', 'p', 'w', '1983', '4849', 'h', '6771', 'p', 'y', '1071', 'u', '6401', '7723', 'p']
Example Output: h, m, p, q, u, w, y

Example Input: ['4255', 'b', '2115', 'r', '4541', 'k', 's', 'i', '7911', 'o', 'c', 'w', '6299', '9031', 'j', 'l', '5425']
Example Output:
b, c, i, j, k, l, o, r, s, w