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]: ['b', 'a', '7411', '4471', 'z', 'l', '2051', 'q', '6749', '8647', 's', 'y', 'h', '9319', 'e', '5419', 'y', 'q']
[EX A]: a, b, e, h, l, q, s, y, z

[EX Q]: ['2633', 'd', 'r', '8083', 'f', 'd', '5121', '8651', 'o', 'b', '811', '7551', 'x', 'p', 'm', 'v', 'm', '7833', '1959', 'y', 'p', '779', '1889']
[EX A]: b, d, f, m, o, p, r, v, x, y

[EX Q]: ['k', '1599', 'x', 'n', 'v', 'o', 't', '4665', 'k', '7879', '735', '4329', '5597', 'a', 'b', 'b', 'c']
[EX A]:
a, b, c, k, n, o, t, v, x