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:
['o', 'h', 'z', 'n', 'e', 'y', 't', '4371', 'm', '1059', '4853', '8529', 'l']
answer:
e, h, l, m, n, o, t, y, z


question:
['5489', 'f', '6833', 's', 'c', '6575', 'w', '2957', '8465', 'v', 'h', '2119', '7731', 'e', '5367', 'e', '3357', 'p', '7565', 'n', 'x', 'n', 'f', '1075', '5941', '6505', 'j', 'p', '2853', 'l', 'q', '4727', 's']
answer:
c, e, f, h, j, l, n, p, q, s, v, w, x


question:
['f', 'x', 'e', 'e', 't', 'p', '9953', 'x', 'q', 'c', '1791', '9145', '3955', 'h', 'e', '2103', '7301']
answer:

c, e, f, h, p, q, t, x