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.

['o', 'v', 'w', '7939', '571', '395', '3707', 'm', 'd', 'u', 'o', 'r', '4211', '9645', '8731', '2441', 'y', '8147', '8809', 'e', 'b', '6835', 'i', '2083', 't', '3481', 'f', 'f', '5559', '3601', 'e', '5637', '5185', 't', '6777', '3419', '8637', 'p', 's', 'o', 'x']
b, d, e, f, i, m, o, p, r, s, t, u, v, w, x, y

['h', 'l', 'i', '1507', 'h', '409', '6777', 'u', '5563', '6113', '6513', '9949', '461', 'z', 'm', '2519', 'r', '4699', 'n', 'x', '4645']
h, i, l, m, n, r, u, x, z

['s', '1481', '5281', 'q', '5807', '7535', 'u', 'm', 'i', '5117', 'y', '4357', '3151', 'q', '475', 'm', 'v', '6407', '4661', 'm', 'd', '2335', '8837', '3053', 'y', '2119', 'm', 'l', '6273', 'x', '7937', '3667', '1469', 'r', '8969', 'i', 'b', '7869', 'p', 'e', '4655', 'w']

b, d, e, i, l, m, p, q, r, s, u, v, w, x, y