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: ['p', '9641', '8515', '1207', 'd', 'j', '6617', '5529', 'g', 'a', 'o', 'f', 'y', '4993', '4643', '6087', 'n', '3177', 'y', '9471', '1229', '8211', '7079']

Output: a, d, f, g, j, n, o, p, y


Input: Consider Input: ['w', 'n', '729', '2491', 'n', 'x', '915', '1869', 'z', '8491', '9947', '561', '829', 'n', 't', 'i']

Output: i, n, t, w, x, z


Input: Consider Input: ['1669', '4373', '6051', '1989', '6723', '6567', '5799', '7761', '8635', '4143', 'b', 'j', 'h', '9891', 'q', '2793', 'q', 'i', '1965', 'v', 'v', 'l', 'w', 'a', '5205', '7729']


Output: a, b, h, i, j, l, q, v, w