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]: ['j', '8797', 'i', '5443', 'i', 'f', '7593', 'u', 'h', '3251', 'l', '681', 'y', 'n', 'r', '1699', '1379', '8987', '6955', 'x', 'p', 'x', '553', 'q', '5679', 'q', 'w', '9007', 'r', '8945', '7351', 'a', 'v', 'k', '1309', 'v', 'i', '4161', 'a', 'q', '2919', '6917', '6845']
[EX A]: a, f, h, i, j, k, l, n, p, q, r, u, v, w, x, y

[EX Q]: ['k', 'n']
[EX A]: k, n

[EX Q]: ['z', '7863', 'r', 'y', 'a', '7769', 'o', 'c', '5703', '9745', 'j', '5283', '5761', '437', 'z', '6325', '6507', 'y', '2315', '3015', '8505', '5599', 'y', '1099', 'o']
[EX A]:
a, c, j, o, r, y, z