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]: ['t', 'u', 'y', 'y', 'b', 'x', 'q', '3713', '2679']
[EX A]: b, q, t, u, x, y

[EX Q]: ['r', 'q', '3649', 't', '3941', 'z', '3729', 's', 'g', '6905', 'h', 'v', '1085', '6353', 'a', '9395', '5433', 'a', '2565', 'p', 'a', 'h', '1491', 'j', 'b', 'v', 'e']
[EX A]: a, b, e, g, h, j, p, q, r, s, t, v, z

[EX Q]: ['1907', 'b', '1593', '2525', '3353', 'l', '2645', '5471', '371', 'q', '5773', '5675', 'q', 'd', '4899', '1963', 'a', '7299', 'r', '2657', 'k', 'k', '603', '9493', 'u', 'v', '9489', 'h', '4021', 'l']
[EX A]:
a, b, d, h, k, l, q, r, u, v