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.

[Q]: ['t', 'u', 'y', 'y', 'b', 'x', 'q', '3713', '2679']
[A]: b, q, t, u, x, y


[Q]: ['5553', 'f', '3881', '8867', 's', 'd', 'a', '375', '7889', '3949', '2905', 'w', 'q', 'q', 'd', '4203', 'i', '2601', 'y', 'p', 'k']
[A]: a, d, f, i, k, p, q, s, w, y


[Q]: ['7595', '5303', '3985', 'n', 'w', 's', 'r', 'f', '8237', 'q', 'y', 'f', '3121', '2463', '4597', 'q', '6801', 'f', 'i', '8563', '3267', 'k', '6157', 'f']
[A]:
f, i, k, n, q, r, s, w, y