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: ['w', '491', 'x', 'u', 'z', 'q', '5411', '7629', '8261', '8629', '1441', '5139', 's', 'm', '6463', 'u', 'z']

Output: m, q, s, u, 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: ['6215', 't', '7625', '4717', 'u', 'r', '5271', '8073', 'v', 'b', '2783', 'z', '2677', 'r']


Output: b, r, t, u, v, z