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: ['1985', '729', '169', '1299', 'l', 'z', '6809', '3083', 'w', 'f', '1989', 'z', '889', 'x', 'r', '1601']

Output: f, l, r, w, x, z


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: ['q', 's', 'o', '4497', 'g', 't', '5249', 'b', '1877', 'v', '4779', '6071', 'w', 'a', 'g', 'q', 'a']


Output: a, b, g, o, q, s, t, v, w