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:
['7155', 'y', '145', '7147', 'u', '8453', 'd', '3693', '6471', '5289', 'n', 'p', '8289', '2929', '199', 'e', '8377', '8937', '5315', 't', 'l', '7715', 'c', 'y', 'f', '9999', 'p', '3655', '5489', 'q', '2321', '9881', '2265', 'n', 'v', '455']
answer:
c, d, e, f, l, n, p, q, t, u, v, y


question:
['5499', 'm', '327', 'h', '5765', '4231', 'y', 'g', 's', '883', '9843', '2751', '8967', 'z', '2301', 'l', 'l', 'k', '7843', '7221', '3643', 'k', '5951', 'r', '9441', '235', '3835', 'l', 'e', 'y', '4061', 'l', '1177']
answer:
e, g, h, k, l, m, r, s, y, z


question:
['8047', '8725']
answer:

-1