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]: ['8315', 'b', '4333', 'f', '6507', '6211', '3475', 'c', 'e', '8039', '661']
[A]: b, c, e, f


[Q]: ['d', '1625']
[A]: d


[Q]: ['s', '8393', '413', 'k', 'f', '8943', '2819', 't', 't', '4033', '4499', 'n', 'f', '475', '1221', '2689', 'o', 'j', 'k', 'k', 'x', '9561', '2057', '3329', '7437', '6627', '1393', '699', 's', '9183', '6021', 'i', '8485', '1139', '8407']
[A]:
f, i, j, k, n, o, s, t, x