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]: ['l', 'u', '3901', '341', '5801']
[EX A]: l, u

[EX Q]: ['8235', 't', '1695', '9899', '3633', 't', '1823', 'r', 'x']
[EX A]: r, t, x

[EX Q]: ['y', '963', 'f', '1565', '7805', 'h', 'i', '3799', '4509', 'n', '4171', '7685', 'f', 'v', '3469', 'i', '8609', 'b', '9647', 'l', '4815', '4931', 'f', 'q', '1145', 'u', '451', 'c', 'm', '7153', '289', '8081', 'u', 'c', 'd', '9995', 'b']
[EX A]:
b, c, d, f, h, i, l, m, n, q, u, v, y