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.
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Question: ['c', '4881', '6893', '3729', 'j', '2385', 'q', 'v']

Answer: c, j, q, v


Question: ['1945', 't', '4477', '4439', '6569', '2021', 'y', 't', '2725', '8947', '6921', '1373', '8107', 'g', 'c', 'w', 'x', 'b', '9117', 'k', '6567', '5073', '2307', 'e', 'b', '7405', 'e', 'x', '1419', 'd', 'o', 'n', 'a', '2647', 'z', '1459', 'n', '6137', 'u', 'b', 'q', '4459']

Answer: a, b, c, d, e, g, k, n, o, q, t, u, w, x, y, z


Question: ['6087', '6903', '7665', '2787', '4435', 'b', 'o', '1017', 'c', 'c', 'g', 'e', 'd', '7143', 'c', 'x', 'k', '1121', '4261', '9485', '8429', '9405', 'f', 'd', 'i', 'k', '8843', '1383', '7555', '6019', 'j', 'u', 'r', '3181', 'b', '907', '365']

Answer:
b, c, d, e, f, g, i, j, k, o, r, u, x