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]: ['1945', 't', '4477', '4439', '6569', '2021', 'y', 't', '2725', '8947', '6921', '1373', '8107', 'g', 'c', 'w', 'x', 'b', '9117', 'k', '6567', '5073', '2307', 'e', 'b', '7405', 'e', 'x', '1419', 'd', 'o', 'n', 'a', '2647', 'z', '1459', 'n', '6137', 'u', 'b', 'q', '4459']
[EX A]: a, b, c, d, e, g, k, n, o, q, t, u, w, x, y, z

[EX Q]: ['7417', '2597', '2633', '7721', 'v', 'l', 'p', '4389', 'l', '3965', '6279', 'm', 'v', 'o', 'd', 'o', 'h', 'd', 'r', 'e', '8993', '2711', 'o', 'q', '1399', 'i']
[EX A]: d, e, h, i, l, m, o, p, q, r, v

[EX Q]: ['u', 'g', '4677', 'n', 'r', '7113', '2043', '1379', 'f', '573', 'b', 'p', 'g', '9337', '8077', 's', '979', '7741', '6707']
[EX A]:
b, f, g, n, p, r, s, u