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.

['1749', 'i', 'w', 'j', '3171', '1999', '1037', '4937', '7013', '3593', '287', 'o', 'i', 'j']
i, j, o, w

['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

['o', 'x', '5459', '4615', 'b', 'f', '5411', 'p', '3097', '5607', '4771', 'r', '6563', 'a', 'h', 's', 'b', '2163', 'p']

a, b, f, h, o, p, r, s, x