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: ['4641', '2881', 'c', '4827']

Output: c


Input: Consider Input: ['7561', 'r', '3419', 'k', 's', '5997', 'u', '6635', '7003', '8491', 'i', '9835', 'c', '8827', 'h', 'a', 'j', '7675', '1995', '1223']

Output: a, c, h, i, j, k, r, s, u


Input: Consider Input: ['6297', '7613', 'b', '9439', 'a', '7601', '4537', '1127', 'x', 'm', '3275', '1253', '1561', 't', '9657', '2057', '7179', '6249', 'j', 'b', '625', '7809', '7945', 'r', 'm', 'j', 'q', 's', 'h', '5741', 'z', '8781', '6179', '6373', '5349', 'q', '8579', '5269', 't', 'd', 'g', '69', 'r', '153']


Output: a, b, d, g, h, j, m, q, r, s, t, x, z