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]: ['a', '2579', 'f', '6787', '123', '225', '6499', '4419', 'o', '1785', '7981', 'z', 'b', '2441', '2821', 'o', 'k', '2747', 's', 'u', 'q', '3901', '7629', 'k', 'm', 'q', '6577']
[EX A]: a, b, f, k, m, o, q, s, u, z

[EX Q]: ['s', 's', '3619', '6051', 'h', '213', '3937', 'v', 'p', 'y', '8449', '9337', '5327', 'a', 'a', 'w', '3985', 'n', 'm']
[EX A]: a, h, m, n, p, s, v, w, y

[EX Q]: ['3', '6779', '4365', '6743', 'o', 'q', 'p', 'x', '3435', '4441', '7341', '953', 'l', '8959', 'x', 'x', 't', 'w', 'r', '8535', 'y', '5645', '1233', '5991', 's', 'a', 'r', 'e', 'w', '4911', 'g', '3291', '4779', '1387', '5711', 'b', 's', 'p', '7665', '8639', '1435', 'p', '4829']
[EX A]:
a, b, e, g, l, o, p, q, r, s, t, w, x, y