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: ['2819', 'k', 'u', 'a', '4575', 'a', 't', 'a', 'f', '1507', '415', 'w', 'o', 'o']

Output: a, f, k, o, t, u, w


Input: Consider Input: ['7965', '6465', 'c', '7963', 'j', '6839', '9989', '1019', 'x', '1303', '2633', 'y', '6865', 'a', 'k', '635', '3719', '7229', 'k', 't', 'r', '5741', '9569', '4931', '1125', 'f', '5429', 'c', '2065', '6315', 'e', '6877', '2005', 'x', '7831', '7297', 'm', '3571', 'b', '8617', '2981', 'i', '5105', 'g', 'u']

Output: a, b, c, e, f, g, i, j, k, m, r, t, u, x, y


Input: Consider Input: ['7961', '9807', 'j', 'e', 'b', '5033', 'n']


Output: b, e, j, n