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.

['6209', 'x', 'j', 'w', '7965', '4905', '6297', '4291', '7183', 'a', 'l', '5267', 'r', '5935', 'a', '7865', 'h', 'p', '6117', 'a', 'y', 'y', 't', 'v', '7271', 'e', 'e', 'z', 'i', 'l', '4731', '2059', 'm', '5703', 'k', 'f', '8125', 'e', '7569', 'r', '2287', '593']
a, e, f, h, i, j, k, l, m, p, r, t, v, w, x, y, z

['t', 'm', '7071', 'j', '353', 'n', 'a', 'm', '9211', 'i', '9537', 'q', '7669', '869', '8753', '8071', '375', '9971', 'c', 'n', '5851', 'u', '2491', '2697', '2789', '4683', '879', 'q', 'g', 'p', 'd', 'x', 'r', 'i', '8171', '5449', '2477', '1151', 'z', '3845', '1079', 'j', 'n', 'p', '8199']
a, c, d, g, i, j, m, n, p, q, r, t, u, x, z

['o', '509', 'y', 'd', 'a', 'u', 'c', '691', '1109', 'r', 't', 'e', '3291', '1297', '6243', '3613', 'v', '3667', '9763', 'w', 'y', '4053', 'z', '4801', 'o', '6209', '8879', 'q', 's', '8371', 'x', 'y', 'l', 'q', 'p', 'e', '7173', 'k']

a, c, d, e, k, l, o, p, q, r, s, t, u, v, w, x, y, z