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:
['5433', '4011', '2113', '2299', 'e', '9829', 'd', 'q', 'e', '3921', 'a', 'q', '8953', 'q', 'g', 'w', 'z', 'u', '4425', 'b', 'q', '5315', 'b', 'u', 'h', 'y', '9733', 'b', 'c', '1225', 'a']
answer:
a, b, c, d, e, g, h, q, u, w, y, z


question:
['6143', '9073', 'h', '1459', 'q', '5799', '6555', '525', '7921', '5041', '3273', '383', 'd', '9075']
answer:
d, h, q


question:
['3719', 'e', '1041', 'k', '9775', 'c', 'e', '8463', 'p', 'e', '8333']
answer:

c, e, k, p