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: ['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: ['5973', 'h', '4081', 'i', '8059', 'w', 'j', '6175', 'w', '8685', '5811', 'k', 'n', '5577', '9817', 'v', '8617', 'u', 'y', '3921', 'b', '1027', '5405', 'a', '3501', '6659', 's', 'e', '157']

Output: a, b, e, h, i, j, k, n, s, u, v, w, y


Input: Consider Input: ['5437', 'p', '4481', 'm', '9959', 'j', 'i', 'i', '6271', 'h', 'y', '6861', '3987', 'g', 'b', '519', 'o', 'k', '5055', '5303', 'z', 'k', '879', '3579', '8727', '8235', 'z', '9829', 'd', 'o', '571', '2157', '6047', '8409', '5867', 'j', '6845', '267', 'c']


Output: b, c, d, g, h, i, j, k, m, o, p, y, z