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: ['9117', '1153', 'f', 'b', '9979']

Output: b, f


Input: Consider Input: ['305', '95', 'e', 'q', 'e', '341', 'u', 'w', '5911', '6851', 's', 'u', '2355', 'd', '4151', 'w', '4421', '1129', '8065', 'k', 'q', '3649']

Output: d, e, k, q, s, u, w


Input: Consider Input: ['7701', 't', 'u', 'p', '7771', 's', '6721', 'p', 'k', '9821', 'g', '5161', '3743', 'g', 'z', '5583', 'b', 'a', 't', '9423', '2331', 'h']


Output: a, b, g, h, k, p, s, t, u, z