Definition: 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.
Input: ['e', '2025', 'i', '8243', '7447', '325', '8091', 'r', 'z', '699', '8645', 'b']

b, e, i, r, z