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]: ['2819', 'k', 'u', 'a', '4575', 'a', 't', 'a', 'f', '1507', '415', 'w', 'o', 'o']
[EX A]: a, f, k, o, t, u, w

[EX Q]: ['2165', 'f', '5081', 's']
[EX A]: f, s

[EX Q]: ['2599', 'i', 'e', 'j', '9455', 'o', 'z', 'u', '8191', '8335', '6117', 'n', 'z', '1215', 'f', 'k', '337', '1785', '3777', 'y', 'l', 'l', 'j', 'x', 'a', 'l', 'p', 'a', 'd', 'u', '255', '1775', 'u']
[EX A]:
a, d, e, f, i, j, k, l, n, o, p, u, x, y, z