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', '1367', '5389', '9515']

Output: w


Input: Consider Input: ['j', 's', 'z', 'v', '5401', 'u', '8859', 'i', 'l', 'a', 'p', 'v', 'v', 'o', '3969', '4091', 'y', '6827', '1799', '5163', 'd', 'w', '4795', '5167', 'x', 'q', '2903', '1171', '5279', '449', '7901', 'u']

Output: a, d, i, j, l, o, p, q, s, u, v, w, x, y, z


Input: Consider Input: ['q', 't', '9761', 'y', '8749', '6185', '9531', '9433', 'o', 'p', '7665', 'i', 'w', '7003', 'w', 'm', '1827', '9285', 'l', '6857', '9227', '2749', '3505', 's', '5811', 'e', '6675', 'w', '4967', '349', '7829', 'z', 'v', 'd', '4671', 'k', '7559', '9497']


Output: d, e, i, k, l, m, o, p, q, s, t, v, w, y, z