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: ['1971', 'g', 't', 't', 'x', 'q', 'o', 'm', 'h', '9481', '1729', '5527', 'u', '3157', 's', '8795', 'z', 'g', 'i', '1649', 'p', '65', 's', 'u', '6843', 'r', 'l', 'k', 'n', 's', 'm', '7991', 'u', 'a']
Example Output: a, g, h, i, k, l, m, n, o, p, q, r, s, t, u, x, z

Example Input: ['z', 'l', '1759', 'k', '8197', 'v', '931', '2587', '7219', '3455', 'e', '8135', 'm', 'n', 'm']
Example Output: e, k, l, m, n, v, z

Example Input: ['m', 'c', 'x', '4219', 'm', '4227', 'j', '171', 'm', 'y', 'z', 'k', '2829', 'j', 'u', 'g', 'x', 'k', '4293', '4979']
Example Output:
c, g, j, k, m, u, x, y, z