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]: ['u', '9249', 'u', 't', 'm', 'm', 'n', 'w', '8617', '2729', 'i', 'l', '2971', '3227', 'b', '9017', '4711', 'i', 't', 'r', 'a', 'a', '1701', '6397', '4535', '9167', '6039', '6111', '849', 'p', '8197', '2645', '5147', 'u', 'l', '7419', 'w', 'w', 'k', 'x', 'c', '3377', '4015', '1297', 'f']
[EX A]: a, b, c, f, i, k, l, m, n, p, r, t, u, w, x

[EX Q]: ['u', 'i', '1185', '3795', '5417', 'k', 'b', '2629', '2635', 'z']
[EX A]: b, i, k, u, z

[EX Q]: ['913', 'p', '7367', 'u', '523', '359', 'n', 'k', '3501', 'k', '3235', '9875', 'u', '8819', 'y', '1003', '5461', '5481', '6865', '1237', 't', 's', '5611', '2909', 'b', 'w', '9581', '5517', '5485', '1679', 'b', 'w', 'g', '4689', '1961', '5199', '2587', '5273', 'j', 's', '3929', '4999']
[EX A]:
b, g, j, k, n, p, s, t, u, w, y