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:
['4045', '4739', 'd', 'e', '6789', 'e', 'q', '4909', '9511', 'h', '9543', '6725', 'a', '3683', 'q', 'k', 'd', 'q', 'z', 'b', '3245', '9877', '9155', '7751', 'e', '1015', '2379', 'f', 'y', '1121', '9801', 'c', 'h', 'l', 'f', '67', 'v', 'v', 'y', 'c', '3871', 'v', '5893', 'a']
answer:
a, b, c, d, e, f, h, k, l, q, v, y, z


question:
['u', 'k', 'd', '4393', 'u', 'h', 'q', '833', 'k', 'l', '5749', 'r', '7123', '1003', 'z', '531', 'o', 'u', '6601', '6975', '4905', 'n', 'e']
answer:
d, e, h, k, l, n, o, q, r, u, z


question:
['2495', 'v', '3717', 'e', '8715', '2497', '6305', 'k', '1909', '1453', 'l', 'z', 'e', 'a', '407', '915', 'v', 'f', 'p', 'f', '1913', '5873', '5763', 'x', 'f', '3083', '831', 'k', '2615', 'h', 'b', 'm', '2009', '1675', 't', '337', 'x', 'z', 'j', '2865', '6879', 'q', '1555', '9353', 'g']
answer:

a, b, e, f, g, h, j, k, l, m, p, q, t, v, x, z