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.

[EX Q]: ['6143', 'y', '5505', '9813', 'r', 'v', 'u', '8681', '2387', 'u', 'o', 'm', '9793', 'm']
[EX A]: m, o, r, u, v, y

[EX Q]: ['8829', 'm', '5369', 'q', '5737', '7799', '5705', 'p', 'w', '1983', '4849', 'h', '6771', 'p', 'y', '1071', 'u', '6401', '7723', 'p']
[EX A]: h, m, p, q, u, w, y

[EX Q]: ['3283', 'v', '9307', 'w', '4763', '8379', '5379', '2151', 'q', '7615', '7167', '6329', '7097', 'w', 'q', 'n', '3631', 'h', 'v', 'x', 's', '5767', 'k', '9883', '6185', '1259']
[EX A]:
h, k, n, q, s, v, w, x