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', 'a', 'b']
[EX A]: a, b

[EX Q]: ['g', 'h', 'g', 'g', 's', 'h', '2849', '2705', '1185', 'x', '5789', '8221', 'e', 'x', 'g', 'b', '4903', 'q', '1563', 'r', 'k', 't', '9047', 'p', 'p', '9397', 'u', '7473', 'f', 'o', 'y', '1957', '1039', '9905', 'i', '4829', 'q', 'w', 'k', 'p', 't', '563', 'g', 'l']
[EX A]: b, e, f, g, h, i, k, l, o, p, q, r, s, t, u, w, x, y

[EX Q]: ['f', '4507', 'o', '7095', '7103', '5799', '363', 't', 'r', '5703', '9417', '9583', '513', '1959', 'c', '2737', 'x', 'y', '7989', 's', 'r', 'p', 'f', '7765', 'y', '2747', 't', '3077', '3733', '433', '6205', 'y', '6387', 'c', 'u', '9727', '9209', 'z', '3435', '5625']
[EX A]:
c, f, o, p, r, s, t, u, x, y, z