instruction:
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.
question:
['g', '6867', '7965', '3313', 'k', '1827', '7337', 'u', '1209', '5145', 'w', 'h', '9059', 'u', 'b', '3189', '2837', 'k', 'y', 'e', 'b', '4479', '541', '7103', 'h', 'm', '2177', '6377', '3993', '7167', 'q', '2145', '5007', '9135', '5331', 'e']
answer:
b, e, g, h, k, m, q, u, w, y


question:
['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']
answer:
d, e, g, l, n, p, s, t, x


question:
['6295', '1229', '8177', 'q', '3985', 'x', 'y', '2455', 'v', 's', '1985', 'b', 'f', '7959', 'u', '9323', 'c', '8045', '8645', '1123', 'a', 'v', 'r', 'o', '1145', 'f', '9187', 'i', '2009', 'o', '6921', 'y', 'b', 'w', '7171', '1085', 'b', 'i', '9761', '4267', '853', '673']
answer:

a, b, c, f, i, o, q, r, s, u, v, w, x, y