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]: ['5011', 'l', '925', 'e', 'b', '3077', 'm', '4541', '781']
[A]: b, e, l, m


[Q]: ['y', 'p', 'q', '2157', 'b', 'w', '8875', 'k', 'i', 'd', '9743', '4941', 'b', 'p', '9941', '495', 'h', 'i', '839', 'c', 'h', 'f', 'b', 'a', 'k', 'z', '7549', '4149', 'h', 'j', '1947', 't', 'f', 'c', '1243']
[A]: a, b, c, d, f, h, i, j, k, p, q, t, w, y, z


[Q]: ['991', '7491', 't', 'a', '9747', '8261', 'w']
[A]:
a, t, w