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]: ['7799', '8163', '3389', 'x', 'k', 'm', '6085', 'f', '1131']
[A]: f, k, m, x


[Q]: ['h', '1797', '8211', 'n', 'r', '7707', '2063', '4655', 'x', '5521', '8327', 'g', '7659', 'i', 'x', 'w', '9465', '4625', 'q', '5377', 'r', '225', 'r', 'i', 'e', '4163', 'g', 'g', '3537', 's']
[A]: e, g, h, i, n, q, r, s, w, x


[Q]: ['6711', 'm', '4733', '2815', 'q', 'y', '9849', 'a', '513', '1693', '7507', 'x', 'p', '8033', '3621', 'x', '4823', '183', 'k', '6773', 'r', 'w', '9547', 'm', 'w', '9207', '1453', '7261', 's', '8775', 'i', 'y', 'y', 'v', 'o', '9355']
[A]:
a, i, k, m, o, p, q, r, s, v, w, x, y