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: ['477', '3931', 'g', '5967', 'm', '9845', '1607', 'a', '1749', 'k', 'j', '7945', '9125', 'v', 'n', 's', '5185', '1117', '17', 'x', '4149']

Output: a, g, j, k, m, n, s, v, x


Input: Consider Input: ['2995', '8179', '8131', '5655', 'j', 'q', 'l', '3193', '1823', 'y', 'n', '7645', 's', '5665', 'r']

Output: j, l, n, q, r, s, y


Input: Consider Input: ['7267', 'f', 'n', 'c', '3915', 'g', '6315', '2853', '7491', '2059', '5155', '75', '9535', 'h', '1417', '3551', 'd', 'd', '3271', '2857', '3081', 'b', 'v', 'e']


Output: b, c, d, e, f, g, h, n, v