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]: ['7561', 'r', '3419', 'k', 's', '5997', 'u', '6635', '7003', '8491', 'i', '9835', 'c', '8827', 'h', 'a', 'j', '7675', '1995', '1223']
[EX A]: a, c, h, i, j, k, r, s, u

[EX Q]: ['1971', 'g', 't', 't', 'x', 'q', 'o', 'm', 'h', '9481', '1729', '5527', 'u', '3157', 's', '8795', 'z', 'g', 'i', '1649', 'p', '65', 's', 'u', '6843', 'r', 'l', 'k', 'n', 's', 'm', '7991', 'u', 'a']
[EX A]: a, g, h, i, k, l, m, n, o, p, q, r, s, t, u, x, z

[EX Q]: ['g', 'm', '9329', '4573', '9047', '7449', 'b', 'o', '187', 'a', '521', '4161', '4185', 's', 'p', 'f', '8847', '2363', 'f', 's', '931', 'q', '7845', '8559', '7085', 'v', '4621', 'p', 'g', 'w', 'r', 'a', '995', 'm', '7973', 'z', '989']
[EX A]:
a, b, f, g, m, o, p, q, r, s, v, w, z