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:
['w', 'o', 'l', '1857', 's', 'q', 'j', 'e', '5945', 'g', 'l', '9563', 'e', 'u', '7633', '7977', '4943', 'y', '5621', 'f', '1653', 'c', 'l', '2843', '2125', '7731', '5257', '5667', 'b', 'b', '5765', 'a', 't', '8163', '9785', '5385']
answer:
a, b, c, e, f, g, j, l, o, q, s, t, u, w, y


question:
['m', '8127', '7519', '4543', '2809', '9855', 'n', '6241', 'w', 'w', 'q', 'w', 'p', '8599', '7819', '3817', 'm', 'q']
answer:
m, n, p, q, w


question:
['t', 'h', 'c', 'b', 'v', '5001', '4011', '8171', 'o', '9583', 'v', 'q', '9393', 'h', 'z', 's', '7717', '1809', 'i', 'i', 'a', '937', '201', '563', 'y', 'b', '5541', '7045', 'p', '1387', '7003', '3569', 'z', 'r', '2083', '5265', '7963', '4671', '1771', '1259', '5965']
answer:

a, b, c, h, i, o, p, q, r, s, t, v, y, z