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]: ['2705', 'n', 'r', '8259', '6839', '3239', 'w', 'z', '2611', '2957', '2303', '6315', '7801', 'c', 'w', 'm', '5049', '6465', '599', 'h', 'q', '7559', 'n', '9917', 'v', 'l', '643', '6415', '3587', 'c', '917', '4435', 'p', 'a', '317']
[EX A]: a, c, h, l, m, n, p, q, r, v, w, z

[EX Q]: ['w', '743', '5757', '8731', 'k', 'p', '317', 'n', 'x', '5649', 'l', 'm', 'c', '2499', 'l']
[EX A]: c, k, l, m, n, p, w, x

[EX Q]: ['s', '9993', 'q', 'h', 'k', 'n', 'p', '4833', 'b', 'l', '9031', 'e', 'x', '7769', '9265', '3953']
[EX A]:
b, e, h, k, l, n, p, q, s, x