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:
['1197', '305', 's', '1113', 'n', '2207', 'e', '227', '2833', '607', '3049', 'v', '4615', 'a', 'k', 'r', 's', '3571', 'f', '4215', 'f', '8985', '5559', '4111', 'u', '1433', '1943', '8831', 'w', 'x', 'o', '9023', 'u', 'y', 'p', 's', 'h', '8877', 'p', 'n', '8903', '5811']
answer:
a, e, f, h, k, n, o, p, r, s, u, v, w, x, y


question:
['w', 'a', 'm', 'd', '409', 'm', 'v', 's', '7801', 'l', '8551', 'k', '867', 'n', '7731', 'z', '3773', '9137', 'v', 's', 'p', 'p', 'f', 'z', 'g', 'q', 'g', '877', '697', '2057', '8389', '2399', '5263', '2761', '9841', '1781', 'l', '8023']
answer:
a, d, f, g, k, l, m, n, p, q, s, v, w, z


question:
['h', '295', 'i', '5269', 'b', 't', 't', 'd', '4631', '4023', 'z', '8795', '6941', 'w', '6571', '2741', '5633', '3363', 'x', '1977', 'z', '1489', '959', 'y', '7895', 'm']
answer:

b, d, h, i, m, t, w, x, y, z