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: ['m', '6761']

Output: m


Input: Consider Input: ['4269', '1847', '2025', '601', 'g', 'n', 'h', '3499', '4977', '3579', '9355', '3489', 'm', 'm', '4401', '4605', 'l', '3977', 'h', 'd', 't', '5135', '7787', 'k', 'q', '7699', '5325', '6269', '1865', 'h', '8915', '5677', 'g', '603', '1435']

Output: d, g, h, k, l, m, n, q, t


Input: Consider Input: ['2643', 's', '5805', '3903', 'n', '4317', '8265', 'b', 'q', '9713', 'n', '7859', 'q', 'n', '2695', 'y', 'v', '8897', '2127', 'n', 'k', 'v', '5773', 'e']


Output: b, e, k, n, q, s, v, y