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.

['7591', '1403']
-1

['n', 'h', 'h', 'e', 'p', '1265', '4853', '9433', '1227', '1619', '6381', 'o', '8285', 'k', 'u', '7471', 'm', '6887', '6579', '5813', '5563', '8535', 'n', '3743', 'h', 't', '4497', '2791', 'e', 'v', '6769', '7969', 'x', 't', 'x', 'q']
e, h, k, m, n, o, p, q, t, u, v, x

['5081', 'w', 'r', '7845', 'w', 'g', 'c', '5769', '5415', 'a', '2935', '3481', 'q', 'u', 'u', 'k', '4861', '5369', 'p', 'i', '4983', '7519', 'w', 'z', '5235', '5941', 'w', 'f', '6523']

a, c, f, g, i, k, p, q, r, u, w, z