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:
['4993', 'n', '7115', 'f', 'd', 'q', '249', '3203', 'w', '5689', '4103', '7129', '603', 'e', 'z', '5571', '3241', '6029', '2721', '8451', 'o', '7841', 'p', '6271', 'r', 'b', '9481', '4045', 'v']
answer:
b, d, e, f, n, o, p, q, r, v, w, z


question:
['m', 'z', 'd', '4667', 'v', '2881', '887', 's', '9861', 'd', '8821', '125', 't', '4493', '6749', '2983', '309', '6033', 'i', '3421', 'j', '4001']
answer:
d, i, j, m, s, t, v, z


question:
['9853', '8181', 'c', 't', 'o', '2159', '8435', 'h', 'l', 'p', '3991', '2857', 'c', 'm', 'q', 'q', '9089', '2817', '1505', '7793', '1693', '2249', '535', 't', 'q', 'k', 't', '3447']
answer:

c, h, k, l, m, o, p, q, t