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.

['6157', '563', '1217', '5241', '4989', 'f', '6443', 'b', 'g', '9347', '6407', '2743', '977', '9097', 'h', 'u', '9163', 'e', 'v', '881', '2187', 'b', '9161', 'u', 'e', '3813', 'b', '5411', 's', 'o', 'i', 'c', '5483', '8071', 'v', '2981', 'n', 'x', 'a', 'j', '5709', 'n', '5335']
a, b, c, e, f, g, h, i, j, n, o, s, u, v, x