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:
['5293', '2211', 'r', 'j', 'x', 'y', 'u', 'n', 'r', 'l', 'v', '113', 'v', 'e', '1323', '6291', 'a', '7417', 'j', '4175', 'd', '855', 'z', '1123']
answer:
a, d, e, j, l, n, r, u, v, x, y, z


question:
['2181', '7019', 'l', 'z', 'z', 'y', '1245', '4179', '6951', '7249', '2723']
answer:
l, y, z


question:
['o', 'a', '1957', 'b', 'z']
answer:

a, b, o, z