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]: ['5293', '2211', 'r', 'j', 'x', 'y', 'u', 'n', 'r', 'l', 'v', '113', 'v', 'e', '1323', '6291', 'a', '7417', 'j', '4175', 'd', '855', 'z', '1123']
[EX A]: a, d, e, j, l, n, r, u, v, x, y, z

[EX Q]: ['i', '6759', '6055', '6661', '8941']
[EX A]:
i