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]: ['o', 'c', '6469', 'x', '8815', '4441', '6193', 'u', 'm', 'a', '9879', 'p', '8335', 'c', 'z']
[EX A]: a, c, m, o, p, u, x, z

[EX Q]: ['4641', '2881', 'c', '4827']
[EX A]: c

[EX Q]: ['9499', '8119', 'w', 'm', '6691', '7641', 'v', '741', 'q', 'x', '267', 'j', '8119', 'w']
[EX A]:
j, m, q, v, w, x