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.

['6367', 'l', '4369', '571', '3689', 'l', 't', '8797', '2365', '6287', 'c', 'g', '423', 'z', 'k', '3489', 'a', '323', '9257', 'q', '4483', '5133', '2163', '5347', '1209', 'g', '3519', 'v', '3335', '859', 'k', 'r', '1515', 'o', 'd', 'a', '1965', '1025', 's', 'w', '4303', '8679', '2347', 'x', 'b']

a, b, c, d, g, k, l, o, q, r, s, t, v, w, x, z