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]: ['i', 'h', '8299', 'e', 'c', '5543', '5241', 'f', '3985', 'f', 'z', '1245', 'e', 't', 'g', '5199', '9217', 'q', 'j', 'p', '767', 'z', '1803', 'k', '7303', '3187', '2507', '6471', '3337', '6037', '9291', 'a', 'l']
[A]: a, c, e, f, g, h, i, j, k, l, p, q, t, z


[Q]: ['y', 'i', '257', '3695', 's', '6717', '4817', '4117']
[A]: i, s, y


[Q]: ['f', 'w', 'k', '8083', '9971', '8829', 'b', 'd', '1319', '9045', 'a', 'n', 'x', '8481', 'c', 'x', 'i', '9739', '7213', 'n', '9157', 'j', '7731', '9355', '479', '1923', '9547']
[A]:
a, b, c, d, f, i, j, k, n, w, x