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: Consider Input: ['s', 'u']

Output: s, u


Input: Consider Input: ['m', '5005', 'y', 'h', 'w', '3609', 'p', '2539', '3307', 'p']

Output: h, m, p, w, y


Input: Consider Input: ['4069', 'z', 'e']


Output: e, z