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: ['m', '6443', 'd', 'o', 'p', 'q', '3765', 'k', 'm', 'y', 'j', '3531', 'y', 't', '671', 'j', '3699', 'a', 'i', '1843', 't', 'd', '1205', 'k', 'h', '1209', '2913', '1301', 'k', 'd', '1769', '7985', 's', 'p', 'f', '4583']

Answer: a, d, f, h, i, j, k, m, o, p, q, s, t, y


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

Answer: h, i, l, m, n, r, u, x, z


Question: ['z', '6657', '7591', '7637', 'b', '4571', '4057', 'q', 'j', 'y', 'w', '3971', '2431', 'n', '489', 'm', 'n', 'k', 's', 'w', 'b', 'j', 'f', 'h']

Answer:
b, f, h, j, k, m, n, q, s, w, y, z