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: ['7591', '7521', 'm', '1429', 'x']

Output: m, x


Input: Consider Input: ['z', 'h', '2065', '6773', 'v', '151', '8957', 't', 'l', 'j', '7867', 'v', '799', '9009', '4317', 'm', '6921', 'r', '1245', '5637', 'x', '4465', 'f', 'y', '3549', 'e', 'f', 'm', 't', '6281', '4241', '3415', 'z', 'g']

Output: e, f, g, h, j, l, m, r, t, v, x, y, z


Input: Consider Input: ['531', '7329', 'i', 'c', '2333', 'm', '9983', '2383']


Output: c, i, m