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.

Example Input: ['a', 'y', 'v', 'f', 'x', 'k', 'f', 'j', '6245', '6289', 'd', '6909', '8701', 'm', '3277', 'f', 'j', 'j', '9227', '8663', '5771', 'j', 'n', 'u', '7837', 's', '2539', '6363', 'g', 'a', '1009', 'v', '1483', 'x', 'i']
Example Output: a, d, f, g, i, j, k, m, n, s, u, v, x, y

Example Input: ['7591', '1403']
Example Output: -1

Example Input: ['1773', 'k', 'a', 'd', 'c', 'a', 'u', 'q', 'd', 'i', '521', 'm', 'x', 'c', '905', '4981', '4369', 'e', 'j', '8765', 'q', 'v', 'h', '3903', '1165', '513', 'n', '5693', '7797']
Example Output:
a, c, d, e, h, i, j, k, m, n, q, u, v, x