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:
['9467', 'o', '8347', '7125', '7999', '1737', 'h', '7043', '8617', '2033', '9959', '2349', 'p', '9389', '5525', 'w', 'u', 'p', '4703', '9807', 's', 'f', '2359', '7357', '2471', '5447', 'f', 'w', '2865', '6627', '3211', 'y', '23', 'z', 's', '1517', '3553', 'r', '2251']
answer:
f, h, o, p, r, s, u, w, y, z


question:
['4031', 't', 'o', 'c', 'x', '3007', '8329', '6345', '1267', '1017', 'o', 'x', 'l', '4129', 'd', '1987', '487', 'o', 'g', 'j', 'v', 'x', '3983', 'f', 'g', '5759', 'k', 'i', 'o', 'b', 'n', '683', 'j', 'o', 't', '4361', 'u']
answer:
b, c, d, f, g, i, j, k, l, n, o, t, u, v, x


question:
['u', '4591', 'd', '2881', '3777', 'v', 'k', 'x', '2381', '5991', 'o', 'j', '4621']
answer:

d, j, k, o, u, v, x