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:
['4371', '9499', 'e', 'w', '9969', '8367', '2897', '1745', 'i', '7049', '9773', 'h', '9649', 'u', '4673', '8513', '8547', 'z', '1995', '7739', '2215', '171', 'c', '7527', '2479', 't', '5223', 'p', '2313', '3243', '2281', 'r', 'c']
answer:
c, e, h, i, p, r, t, u, w, z


question:
['v', '3765', '4065', 'a', '4201', 'f', 'x', '9275', 'q', '9303']
answer:
a, f, q, v, x


question:
['e', 't', '2449', '5739', '1051', '4905', 'q', 'v', '9299', 'n', 'q', 'o']
answer:

e, n, o, q, t, v