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:
['7073', 'd', 'e']
answer:
d, e


question:
['4009', 'y', '9077', 'p', 'q', '6711', '6443', '5491']
answer:
p, q, y


question:
['m', 'y', '833', 'v', '8795', '6881', 'a', '2079', '4627']
answer:

a, m, v, y