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.

['7823', '2933', 'k', '4139', '5585', 'f', 'c', 'm', '2035', 'q', 'z', 'l', '1999', 'q', 'p', '7291', '2091', 'v', '423', 'e', 's', '6089', '4763', '6739']
c, e, f, k, l, m, p, q, s, v, z

['n', 'q', '6461', 's', '8565', '2237', '2071', '8143', '2977', '5511', 'j', 'o', '5793', 'j', 'm', 'n', '8031', 'j', '535', '5001', 's', 'y', '1737']
j, m, n, o, q, s, y

['2537', '8113', '4293', 'p', '8829', '3601', 'd', 'k', '5355', '9543', 'o', '2961', 'v', '7813', 'w', '2813', 'e', 'c', 'a', 'b', 'u', 'l', 'g', 'b', '5125', '6939', 't', 'o', 's', '4185', 'i', 'a', 'v', '6811', '5211', 'o', 'n', '8153', '7381', 'i']

a, b, c, d, e, g, i, k, l, n, o, p, s, t, u, v, w