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]: ['y', 'u', 'c', '5909', 'x', '9865', 'e', 'h', '5125', '4719', 'w', '8855', 'i', 'd']
[A]: c, d, e, h, i, u, w, x, y


[Q]: ['699', 'd', '6027', 'j', 'e', 'c', 't', '9983', '5471', '2649', 't', '2631', 'r', 'h', '293', 'j', '8699', 'p', 'k', '5433']
[A]: c, d, e, h, j, k, p, r, t


[Q]: ['7805', '7411', 'p', '889', 'd', '4385', 'c', 'c', '2807', 'r', 'z', 'r', '9495', 'k', 'w', 'f']
[A]:
c, d, f, k, p, r, w, z


