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: ['4213', '3595', '7937', 'y', '5723', 'v', 'b', '7007']

Answer: b, v, y


Question: ['4993', '6641', '3127', '9409', '8453', '5909', '6109', 'y', 'f', '6859', 'c', '3863', 't', '1221', '3689', 'w', 'h', '7947', 't', '5979', 'l', 'i', '1321', '3149', 'l', 'v', '3825', 'z', '9297', 'f', 'e', '7205', 'a', 'a', '2645', '391', '4965', 'w', 'h', '7715', '9409', '3603', '4147']

Answer: a, c, e, f, h, i, l, t, v, w, y, z


Question: ['6981', 'q', '1799', '7287', '4565', 'z', '771', 'a', '4635', 'j', 'k', '3225', '6279', 'w', '97', '497', '895', '5769', '627', '3823', 'x', '6773', '3857', '6709', '5343', '6889', 'n', '7377']

Answer:
a, j, k, n, q, w, x, z