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:
['d', 'm', 'k', '3513', '8241', '5541', 'm', 's', '1993', '6163', '2753', 'd', 'b', 'm', 'i', '7647', '8631', '9119', '2165', 'x', '3911', '2769', '1673', '7195', 't', 'w', '5555', 'o', '3265']
answer:
b, d, i, k, m, o, s, t, w, x


question:
['5489', 'f', '6833', 's', 'c', '6575', 'w', '2957', '8465', 'v', 'h', '2119', '7731', 'e', '5367', 'e', '3357', 'p', '7565', 'n', 'x', 'n', 'f', '1075', '5941', '6505', 'j', 'p', '2853', 'l', 'q', '4727', 's']
answer:
c, e, f, h, j, l, n, p, q, s, v, w, x


question:
['t', '7191', 'y', '3445', '7021', '1793']
answer:

t, y