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: ['j', '1733', 'p', '6741', '7933', '8943', '733', 'x', '1107', 'z', '1719', '7653', 'y', 'z', '6563', 'p', '4615', 'j', '4489', 'h', 'w', 'y', 'p', 'c', '7949', 'k', 'm', 'r', '9427', '7243', '9777', 'j', '323', '4095', 't']

Output: c, h, j, k, m, p, r, t, w, x, y, z


Input: Consider Input: ['8373', 'k', '1643', '6891', 'o', '8533', '5851', '651', '9599', '8721', '5929', '2573', 'u', '6215', 'e', '6825', 'y', '2885', 'y', '1043', '1481', 's', 'w', 'e', '6671', '8745', '2801', 'x']


Output: e, k, o, s, u, w, x, y