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]: ['6027', 'v', 'b', 'l', '7853', 'r', 'y', '2919', '3831']
[EX A]: b, l, r, v, y

[EX Q]: ['3611', '6825', 'j', 'e', 'r', 'a', '8889', 'y', 'x', 'k', '2651', '4545', '2289', 'r', 'q', '3163', 'a', 'i', 'j', 't', 'b', '2673', '4307', 'q', '5839', 'w', 'g', '6221', 'g', 'h', 'h', '5815', 'n', '3551', '7709', 'z', '2281', '7987', 'w', 'a', '2319', '3337', '3409']
[EX A]: a, b, e, g, h, i, j, k, n, q, r, t, w, x, y, z

[EX Q]: ['4505', 'g', 'b', 'l', 'l', '9997', 'g', 'u', '9663', 'z', 'h', '4991', '8483', 'e', '8411', '197', 'k', '133', '9737', 's', '2725', 'o', 'a', '9839', '2597', '6147', '9209']
[EX A]:
a, b, e, g, h, k, l, o, s, u, z