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:
['1197', '305', 's', '1113', 'n', '2207', 'e', '227', '2833', '607', '3049', 'v', '4615', 'a', 'k', 'r', 's', '3571', 'f', '4215', 'f', '8985', '5559', '4111', 'u', '1433', '1943', '8831', 'w', 'x', 'o', '9023', 'u', 'y', 'p', 's', 'h', '8877', 'p', 'n', '8903', '5811']
answer:
a, e, f, h, k, n, o, p, r, s, u, v, w, x, y


question:
['2313', '2073', 'd', 'e', 'o', '793', '4999', 'f', 'c', '4473', '4519', 'u', 'n', 'k', '69', '475', 'a', 'j', 'q', 'x', '5869', '9523', 'z', 'v', '9265', '5989', 'p', 'm', 'g', 'y', 'b']
answer:
a, b, c, d, e, f, g, j, k, m, n, o, p, q, u, v, x, y, z


question:
['7081', 'n', 'a', 't', '4905', '6563', 'y', 'r', 'c', 'q', 'u', '887', '7499', '5361', '1451', '6889']
answer:

a, c, n, q, r, t, u, y