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:
['o', '4167', 'b', '1651', '8327', '9219', 'o', 'v', '5841', '6057', 'i', 'q', 'o', 'r', 'a', '7069', 'y', 'h', 'd', '3775', 'j', 't', '3663', '55', '7117', 'e', 'u', 'm', '931', '5777', '8773', '4891']
answer:
a, b, d, e, h, i, j, m, o, q, r, t, u, v, y


question:
['f', 'w', 'y', 't', '5269', '9989', 'p', 'v', '6609', 'v', 'c', 'q', 'm', '6565', '189', 'm', '3617', 'b', '9147', '665', 'v', '5989', '1511', '3123', '6667', '4661', '185', 'b', '3405', 'b', '6027', 'n', '6973', '505', 'g', '815', '3439', '2069', '291', 'j', 'f', '1121', '8009', 'm', '8353']
answer:
b, c, f, g, j, m, n, p, q, t, v, w, y


question:
['8037', 'z', 'm', 'v', 'd', 'g', '7207', 'p', 'f', 'i', 'k', '3083', 'v', '8229', 'f', '5721', '5215', 'w', '6383', 'r', 'f', 'y', 'l', '4191', 'x', 'c', 'k', 'j', 'y', '4455', 'h', '5693', 'x', 'd', '9507', 'm', '2191', '389', 'm']
answer:

c, d, f, g, h, i, j, k, l, m, p, r, v, w, x, y, z