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.

Example Input: ['7997', 'm']
Example Output: m

Example Input: ['n', '7337', '6887', '2203', '4663', '2837', '6451', '959', '8027', 'p', 'v', 'q', 'g', '8059', '6151', 'v', '7097', '6583', '7637', '2367', 'w', '9603', '5365', '3773', '1707', 'k', 'x', 's', 'c', 'u', '3641', '6137', '1207', 'k', '5531', '4543']
Example Output: c, g, k, n, p, q, s, u, v, w, x

Example Input: ['869', 'j', 't', 'g', '8121', 'j', '5291', 'i', '8579', 'f', '3991', '1029', '1703', '8681', '6237', 'q', '5135', '7105', '4853', '4787', 'x', '7417', '6277', '6419', 'y', 's', '1853', '5899', 'e']
Example Output:
e, f, g, i, j, q, s, t, x, y