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: ['5761', '2289', '577', 't', '125', 'i', 'g', '9693', '747', 'd', '4829', '9587', 'f', 'k', 'w', 'v', '8607']

Output: d, f, g, i, k, t, v, w


Input: Consider Input: ['t', 'r', '2959', '2517', 'a', '9959', '729', '511', 'y', 'r', '465', 'c', '687', 'm', 'b', 'm', '3449', '9713', 'g', '8275', '8823', 'a', 'z', 'w', '2185', '6283', '8457', '8137', '7163', '8329']

Output: a, b, c, g, m, r, t, w, y, z


Input: Consider Input: ['b', '7141', '7837', '2979', 'f', '9087', 't', 'w', '757', 'd', '4339', 'j', 's', '4053', '5907']


Output: b, d, f, j, s, t, w