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]: ['8315', 'b', '4333', 'f', '6507', '6211', '3475', 'c', 'e', '8039', '661']
[EX A]: b, c, e, f

[EX Q]: ['s', 's', '3619', '6051', 'h', '213', '3937', 'v', 'p', 'y', '8449', '9337', '5327', 'a', 'a', 'w', '3985', 'n', 'm']
[EX A]: a, h, m, n, p, s, v, w, y

[EX Q]: ['m', '7981', '3451', '987', 'h', '9663', 'b', '8475', '4467', '4821', 'g', 'h', 'v', '6609', '5041', 'm', 'e', '7517', '7455', '8977', '5955', '4653', '1903', '9461', '1589', '7561']
[EX A]:
b, e, g, h, m, v