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]: ['x', 'b', '1467', 'y', '2101', 'y', 'm', '2745', 'z', '429', '7523', 'e', 'f']
[A]: b, e, f, m, x, y, z


[Q]: ['2161', '8009', '3057', 'r', '3897', 'd', 'j', '2727', 'b', '3231', 'i', '9227', '393', '5799']
[A]: b, d, i, j, r


[Q]: ['z', 'c', '2493', '4945', 'a', 't', 'f', '7121', '3237', 'u', 'q', '551', 'o', 'f', 'f', 'x', '7441', 'a', 'g', 'y', 'm', '9575', 'j', 'm', '8691']
[A]:
a, c, f, g, j, m, o, q, t, u, x, y, z