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.

['g', '7517', '3173', 'd', '2143', 'n', '8507', 'l', '8369', '225', 'e', 'l', '9511', 'p', '1317', '5651', 'p', '1125', 't', '739', '6453', 'l', 'g', '8555', '8075', 'x', 's', 'd']
d, e, g, l, n, p, s, t, x

['x', 'i', 'k', 'c', 'f', '3057', '481', '5887', '847', 'c', 'x', 't', 'g', '5805', 'a', 'i', '2885', '403', 'x', 'c', '4815', '2765', 'c', '5181', 'l', 'e', '3843', '1171', 'u', '7867', 'z', 'e', '9349', '5011', 'h', 'x', '3193', 'i', '4595', '8621', '6007', '1879']
a, c, e, f, g, h, i, k, l, t, u, x, z

['u', 'g', '2007', 's', '2773', '29', '1581', 'l', 'y', 'k', '5011', '9439', 'r', 'z', '7187', '6527', '7241', '2539', '6115', 'd', 'm', 'w', 't', '9955', '8083', '4973', 'b', '5887', 'a', 'p', 'a', 'c', '5129', 'i', '27', '285', '3243', '4057', 'a']

a, b, c, d, g, i, k, l, m, p, r, s, t, u, w, y, z

