Given the task definition and input, reply with output. 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.

['6679', 'k', 'j', '4111', 'f', '4589', 'o', '9629', '4965', 'x', 'g', '4185', '1339', 'q', 'c', '2185', 'i', 'n', 'l', 'f', 'q', '2387', 's', 'e', 'v', 't', '5499', 'x', '3535', '6601', 'n', '7485', '9155', 'u', '9637', 'e', 'a', '703']

a, c, e, f, g, i, j, k, l, n, o, q, s, t, u, v, x