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:
['5089', '6113', 'v', 'l', '5529', 'q', '7499', 'e', 'r', 'c', '5999', '2619', 'a', '2523', '7697', 'j', 'c', '6537', '8313', '5623', '4225', '7677', 'q', 'a', '6559', 'y', 'b', 'm', '7645', '7019', 'r', 'i', '5225', '703', 'i', '6189', 'f', 't', '7553']
answer:
a, b, c, e, f, i, j, l, m, q, r, t, v, y


question:
['2799', '7519', '345', 'e', 'l', '9369', '4703', '4111']
answer:
e, l


question:
['9299', '9153', '6145', 'w', '3091', '7533', '2005', 'b', 'u', '7193', 'q', '4305', 'w', '3935', '7419']
answer:

b, q, u, w