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]: ['l', 'g', 'd', 'p', '8163', '6643', 'o', 'p', 'm']
[EX A]: d, g, l, m, o, p

[EX Q]: ['j', '6675', 'u', 's', '705', '8227', 'f', 'w', 'n']
[EX A]: f, j, n, s, u, w

[EX Q]: ['8699', '9373', 'i', 'g', 'i', '4935', 'i', '5191', 'y', 'k', '5277', '3367', '6005', '6025', 'j', 'r', 'y', 'g', 'e', 'b', 'v', 'l', '6367', '5947', '2533']
[EX A]:
b, e, g, i, j, k, l, r, v, y