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]: ['887', 'p', '3819', '2727', '1407', 'b', 'n', '737', 'd', 'w', 'q', '6877']
[EX A]: b, d, n, p, q, w

[EX Q]: ['b', 'd', '8153', 'u', '3695', '5317']
[EX A]: b, d, u

[EX Q]: ['5509', 'h', 'm', '9955', 'o', 'v', 'b', 's', 'f', 'q', '5217', 'a', 'n', '2919', '5411', '9095', 'l', 'q', 'k', 'o', '9937', '8997', '9035', '8479', 'p', '2259', '8757', '8289', 'c', '2839']
[EX A]:
a, b, c, f, h, k, l, m, n, o, p, q, s, v