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:
['a', 'y', '7401', 'e', 'l', '4351', 'p', '5673', 'k', '333', 'o', 'd', 'e', 'j', 'e', '9569', '1795', 'r', 'z', '6059', '4399', '2927', 'n', '9387', '9317', 'b', 'c', 'e']
answer:
a, b, c, d, e, j, k, l, n, o, p, r, y, z


question:
['6143', '9073', 'h', '1459', 'q', '5799', '6555', '525', '7921', '5041', '3273', '383', 'd', '9075']
answer:
d, h, q


question:
['k', '7993', '4623', '1965', 'k', 'p', 'q', '9757', 'z', 'g', 'm']
answer:

g, k, m, p, q, z