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.

['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']
c, g, k, n, p, q, s, u, v, w, x

['l', '6819', '1029', '2925', '2361', '5545', '2151', '2681', 'f', 'p', '1263', '2875', 'b', '4665', 'f', 'g', 'p', '4829', '8453', 'z', 'l', '4219', '7517', '25', 'a', '5099', '3693', 'i', '1815', '1541', 'g', '7665']
a, b, f, g, i, l, p, z

['945', 'w', '1745', '1995', '9741', '3199', 'h', 'u', 't', '1889', 'x', 'v', '6809', '2543', '1853', 'q', '8623', 'k', '821', 'e', 'u', 'l', 'p', 'u', '105', '4303', 'y', '7389', '2399', 'x', '5105', 'u', 'x', 'i', '6777', '2881', '9053', '8405', 't', '1069', 'b']

b, e, h, i, k, l, p, q, t, u, v, w, x, y