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: ['9117', '1153', 'f', 'b', '9979']
Example Output: b, f

Example Input: ['8315', 'b', '4333', 'f', '6507', '6211', '3475', 'c', 'e', '8039', '661']
Example Output: b, c, e, f

Example Input: ['4335', 'x', 'm', '7729', '7737', '5339', 'p', '8447', 'c', '9801']
Example Output:
c, m, p, x