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.

[EX Q]: ['r', 'n', '7583', '8697', '7927', 'l', '5003', '1363', 'p', 'e', 'q', '6227', '6915', '8619', '9011', 'n', '3063', '3799']
[EX A]: e, l, n, p, q, r

[EX Q]: ['s', 'c', 'e', '2457', '9413', 'r', '9949', 's', 'z', 'e', 'a', 'o', '7207']
[EX A]: a, c, e, o, r, s, z

[EX Q]: ['t', 'q', '3871', '1811', 'n', '6283', 'v', '7211', '483']
[EX A]:
n, q, t, v