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.

['8859', '575', 'l', 'e', '6575', '1303', '8643', '1395', '3171']
e, l

['2943', 'k', '8519', '9103', 'j', '2461', '1049', '2211', '8761', 'l', 'e', '8939', '6013', 'r', '9089', '5781', '5383', '5495', '6699', '7307', '2733', '933', '9865', 'g', '6471', '3179', 'm', '8231', 't', 'e', 'u', '9909', 'g', 'g', '9431', '6521', 'y', 'g', '1415', 'e']
e, g, j, k, l, m, r, t, u, y

['s', '7143', 'u', '2021', '9889', 'q', 'g', '6223', '5039', '2447', '8663', 'u', 'o', 'p', '6293', '3291', 'p', '3907', 'p', '5195', '4823', '591', '9559', '4019', '265', '4797', 't', 'q', '9629', '9471', '3851', 'l']

g, l, o, p, q, s, t, u