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: ['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: ['g', '7517', '3173', 'd', '2143', 'n', '8507', 'l', '8369', '225', 'e', 'l', '9511', 'p', '1317', '5651', 'p', '1125', 't', '739', '6453', 'l', 'g', '8555', '8075', 'x', 's', 'd']

Output: d, e, g, l, n, p, s, t, x


Input: Consider Input: ['9807', '8661', 'l', '8885', '5029', 'g', 'f', '4571', '2871', 'm', '2035', '1245', '1149', 't', 'q', 'j', '5303', 'q', '1665', '6839', 'q']


Output: f, g, j, l, m, q, t