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:
['9467', 'o', '8347', '7125', '7999', '1737', 'h', '7043', '8617', '2033', '9959', '2349', 'p', '9389', '5525', 'w', 'u', 'p', '4703', '9807', 's', 'f', '2359', '7357', '2471', '5447', 'f', 'w', '2865', '6627', '3211', 'y', '23', 'z', 's', '1517', '3553', 'r', '2251']
answer:
f, h, o, p, r, s, u, w, y, z


question:
['l', 'i']
answer:
i, l


question:
['7693', '6217', '3453', 'k', 'y', 'w', '61', 'z', '3135', 'e', 'l', 'h', 'u', 'e', '5625', 'w', 'k', '2353', '4309', '6103', '4221', 'x', '5339', '8861']
answer:

e, h, k, l, u, w, x, y, z