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.

['n', 't', '2901', '9697', 'a', 'j', 'x', 'a', '4437', '2255', '2177', 's', '3173', 'j', 't', '5713', '4091', '4253', '5553', 'i', '4533', 'i', 'e', '6899', 's', '3541', '2139', '2705', 'm', 'u']
a, e, i, j, m, n, s, t, u, x

['s', 'c', 'e', '2457', '9413', 'r', '9949', 's', 'z', 'e', 'a', 'o', '7207']
a, c, e, o, r, s, z

['565', '3523', '4641', 'h', '4723', '1049', 'o', '7697', 'b', '6625', '1311', 'x', '6035', '4213', '257', 'v', 'x', 'a', 'w', '9197', 'q', 'm', 'l', 'h', 'q', '7645', '9205', 'n', '8223', '1579', 'n', 'r', 'n', '1501', '6373', '25', 'k', 'x', '6123', 'z', 'q', '2525', 'g', 'k', '4631']

a, b, g, h, k, l, m, n, o, q, r, v, w, x, z