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', 'o', '8161', 's', '3653', 'v', 'c', 'e', '5353', 'h', '9145', '333', 's', '7689', '8277', 'a', 'o', 'h', 'z', 'w', '9297', 'w', '9383', '8963', 'k', 'x', 's', 'w', 'h', 'j', '5737', 'o', '2247', '3723', '2043', '4615']
answer:
a, c, e, h, j, k, o, s, v, w, x, z


question:
['v', 'l', 'v', '7673', '8975', 'u', '2471', '4151', '3615', '1139', 'i', 'z', '8833', 'v', '341', 'l', 'n', 'l', 'd', '9207', '1861', '3901', 'a']
answer:
a, d, i, l, n, u, v, z


question:
['7803', '1811', 'w', '7095', '4803', '89', 'j', 'v', 'd', '1619', '2371', '2543', '1873', 'k', 'y', 'i', '6625', 'w', 'g', 's', 'm']
answer:

d, g, i, j, k, m, s, v, w, y