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.

Example Input: ['2165', 'f', '5081', 's']
Example Output: f, s

Example Input: ['2527', '9123', '8717']
Example Output: -1

Example Input: ['q', '4423', 'p']
Example Output:
p, q