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: ['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: ['4045', '4739', 'd', 'e', '6789', 'e', 'q', '4909', '9511', 'h', '9543', '6725', 'a', '3683', 'q', 'k', 'd', 'q', 'z', 'b', '3245', '9877', '9155', '7751', 'e', '1015', '2379', 'f', 'y', '1121', '9801', 'c', 'h', 'l', 'f', '67', 'v', 'v', 'y', 'c', '3871', 'v', '5893', 'a']

Answer: a, b, c, d, e, f, h, k, l, q, v, y, z


Question: ['5049', 'b', '6785', '7339', 'i', '913', 'k', 'i', 'd', 'w', '1245', 's', 'l', 'w', '3281', 'b', 't', '6947', '6233', '7641', 'r', 'b', '7789', 'c', '9879', 'e', '8109', '1527', '4557', '603', '1995']

Answer:
b, c, d, e, i, k, l, r, s, t, w