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', 'g', 'd', 'p', '8163', '6643', 'o', 'p', 'm']
[EX A]: d, g, l, m, o, p

[EX Q]: ['x', 'j', '9747', 'i', '2015', '3505', 'q', 'n', 'h', '3011', 'u', '8043', 'j', 'f', 'd', 'a', 'p', '5817', 'l', 'q', '2275', 'n', '7085', '5373', 'l', 'g', 'b', '8043', '3085']
[EX A]: a, b, d, f, g, h, i, j, l, n, p, q, u, x

[EX Q]: ['5519', '6677', 'b', '2959', '9131', '4803', '2971', '319', '4389', 'w', 'q', 'o', '1953', 'r', '7705', '9463', '8697', 'o', 'r', '6533', '4257', 'm', '4167', 't', '7609']
[EX A]:
b, m, o, q, r, t, w