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]: ['8311', 'w', 'f', '3431', '9863', '5817', '3969', '2705', 'x', 'm', 'k', 'z', 'z', '235', 'x', '417', 's', 'i', 'y', '8833', '8675', 's', 'm', '2149', '765', 'u', '1021', '7823', 'x', '7275', '3157', 'k']
[A]: f, i, k, m, s, u, w, x, y, z


[Q]: ['7677', '4069', 'b', 'w', '4381', 'b', '5757', '711', '765', '8347', '6547', '9527', '945', '5333']
[A]: b, w


[Q]: ['k', 'w', '2881', 't', 'c', 'm', '3443', 'g', 'f', 'u', '803', 'h', 'p', 'c', '6401', 'e', '5671', 'i', '3555', '3211', 'p', 'z']
[A]:
c, e, f, g, h, i, k, m, p, t, u, w, z