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:
['h', 'v', '1263', 'y', '3299', 'd', 'a', 'h', 's', '2007', '7597', '1015', 'k', '6643', '6959', 'g', 'u', 'd', '5737', 'n', 'z', 'y', 'b', 'g', '9059', '7349', 'j', 'w', 'i', 'z', 'p', '5809', 'x', '4421', 'g', '6399', '3965']
answer:
a, b, d, g, h, i, j, k, n, p, s, u, v, w, x, y, z


question:
['7065', 'f', 'k', 'i', 'd', '8291', 'z', 'e', 'q', '5345', 'h', '3397', 's', '5355', 's', '9033', 'e', '5241', '5285', 'm', 'h', 'i', 'n', '6471', '3365', 'f', 'r', '6145', 't', '4869']
answer:
d, e, f, h, i, k, m, n, q, r, s, t, z


question:
['i', '4541', 'p', 'a', 'i', '1373', '4059', 'q', 'a', 'n', '8983', '523', 'q', '2787', 'x', '6819', 'o', '3777', '2603', '4817', '2795', 'o', '6357', 'g', 'v', 'i', 't', '641', 'd', 'm', '1435', 'x', 's', '9421', '3243', 'l', '7949', 'd', '1005', '9513', '8449', 'b']
answer:

a, b, d, g, i, l, m, n, o, p, q, s, t, v, x