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.

['7155', 'y', '145', '7147', 'u', '8453', 'd', '3693', '6471', '5289', 'n', 'p', '8289', '2929', '199', 'e', '8377', '8937', '5315', 't', 'l', '7715', 'c', 'y', 'f', '9999', 'p', '3655', '5489', 'q', '2321', '9881', '2265', 'n', 'v', '455']
c, d, e, f, l, n, p, q, t, u, v, y

['2313', '2073', 'd', 'e', 'o', '793', '4999', 'f', 'c', '4473', '4519', 'u', 'n', 'k', '69', '475', 'a', 'j', 'q', 'x', '5869', '9523', 'z', 'v', '9265', '5989', 'p', 'm', 'g', 'y', 'b']
a, b, c, d, e, f, g, j, k, m, n, o, p, q, u, v, x, y, z

['6981', 'q', '1799', '7287', '4565', 'z', '771', 'a', '4635', 'j', 'k', '3225', '6279', 'w', '97', '497', '895', '5769', '627', '3823', 'x', '6773', '3857', '6709', '5343', '6889', 'n', '7377']
a, j, k, n, q, w, x, z