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: ['8821', '9833', 'l']

Output: l


Input: Consider Input: ['9833', '3383', 'h', '3545', '2899', 'y', 'p', 'q', '1901', '3317', '5641', 'v', 'c', 'u', '5521', 'e', '7997', '2439', '5573', '4119', 'k', '8291', '1009', '8253', '405', '233', 'p']

Output: c, e, h, k, p, q, u, v, y


Input: Consider Input: ['4725', '5177', '7125', 'c', 'g', 'i']


Output: c, g, i