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:
['2165', 'f', '5081', 's']
answer:
f, s


question:
['7441', '7967', '2011', '1383', 'i', '3623', 'b', 'y', 'e', '1593', 'r', 'a', 'd', 'b', '6159', '3931', '989', '435', 'o', 'y', 'j', 'w', '7669', 'y', '5781', 'u', '531', '7467', '3971', '8139', 'w', 'a', '5113', '9461', '8377', '7431', '6975', '6055', '7307', 'v']
answer:
a, b, d, e, i, j, o, r, u, v, w, y


question:
['r', '399', '7215', '161', 'g', '7587', 'e', 'm', '4987', '9733', '9297', '5301', '1923', 's', '2645', '2433', '5393', '8377', '2959', '2039', '6435', '2295', '7545', 'j', '2521', '4613', '4493', 'l', '2339', '4079', '7279', '1093', 'k', 'x', '6541', '4821', 'n', '757', '9663', 'n']
answer:

e, g, j, k, l, m, n, r, s, x