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: ['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: ['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: ['5633', 'l', 'm', '9231', 'a', 'c', 'z', 'h', '2473', 'x', 'x', '539', '2109', '3741', '3733', 'u']


Output: a, c, h, l, m, u, x, z