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:
['x', 'u', 'm', '8089', '9985', 'e', '2927', 'n', '7085', 'q', 'v', 'f', 'p', '5079', '3339', '7871', 'h', '7389', '733', 'e', '3387', 'b', 'x', 'z', '2039', 'u', '59', '5031', '8115', '5447', '3045', 'x', '6591', '9561', '4315']
answer:
b, e, f, h, m, n, p, q, u, v, x, z


question:
['2915', '6033', '5541', '4685', '1263', '6701', 's', '7269', 'g', '8033', '8171', '6917', 'l', '2913', '447', 'g', 'a', 'z', 'o', '7563', '5385', '5259', '5067', '4869', '2653', '6925', '7001', '8553', 'x', '1243', '9131', '5037']
answer:
a, g, l, o, s, x, z


question:
['v', '6831', '767', '3247', 'a', 'u', '7717', 'q', '6657', 't', 'j', 'h', 'l', 'd', 'f', 'e', 'n', 'w', 'k', 'c', '4209', 'y', '8529', 'y', 'q', '6439', 'r', 't', 'r', '711', '6967', '1991', '8047', 'e', '8773', 'f', '1069', 'f', 'e', 'u', '6051', '7175', 's', '7391']
answer:

a, c, d, e, f, h, j, k, l, n, q, r, s, t, u, v, w, y