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

[EX Q]: ['s', 'w', '8949', '4025']
[EX A]: s, w

[EX Q]: ['5031', 'v', '7723', 'n', 'c', 'x', 'h', 'p', 'g', '6247', 'w']
[EX A]:
c, g, h, n, p, v, w, x