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: ['t', '3035', '7175', '53', '277', 'e', 'b', '965', 'a', 'z']

a, b, e, t, z