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: ['h', '7189', '5179', '8513', 'b', 'r', '1333', '6499', 'i', '7589', 'b']

b, h, i, r