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: ['57', 'j', 'n', '877', 'u', 'w', 'j', 'f', '8977', 'h', '469', '9417']

Output: f, h, j, n, u, w


Input: Consider Input: ['a', '7599', 'i', '9455', '3955', '2015', 'j', '7345', 'x', 't', 'c', '1317', '9155', '6383', '7793', 'n', '5581', 'v', '3485', 'n', 'r']

Output: a, c, i, j, n, r, t, v, x


Input: Consider Input: ['g', 'p', '2925', 'n', 'o', 'y', '6381', 'l', '4963', 'g', 'm', 'u', 't', '9389', '3787', '7713', '1251', '779', 'i', 'w', '9869', 'y', 'y', '3881', 'k', 't']


Output: g, i, k, l, m, n, o, p, t, u, w, y