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.

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

Output: h, m, p, q, u, w, y


Input: Consider Input: ['n', 'y', '7087', '9539', 'x', 'i', 'w', '7237', '8613', 'k', '5999', '4179', 'o', 'm', '7485', '1955', 'w', '1451', 'h']

Output: h, i, k, m, n, o, w, x, y


Input: Consider Input: ['o', 's', 'm', '2609', 'a', 'x', 'f', 'g', 'p', '7289', 'z', '991', '7289', 'g', 'b', '7379', 'd', 'r', 't', '6845', '8947', '9601', '9405', 'i', 'w', 'i']


Output: a, b, d, f, g, i, m, o, p, r, s, t, w, x, z