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:
['5163', 'n', 'j', '67', '3801', 'n', '7113', 'z', '579', '6885', '8921', 'v', '5481', '5507', 'k', '8403', 'c', '837', 'u', '6341', 'd', 'i', '497']
answer:
c, d, i, j, k, n, u, v, z


question:
['3191', '2655', '239', '2585', '3369', '7815', '5919', '8269', '5633', 'x', '8085', '2909', 'y', '2465', 'i', '1579', 'u', '2371', 'l', '1949', '51', 'e']
answer:
e, i, l, u, x, y


question:
['e', 'u', 'b', '9193', '9317', 'f', '6841', 'b', '4143', '5113', 'o', 'h']
answer:

b, e, f, h, o, u