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: ['j', '8797', 'i', '5443', 'i', 'f', '7593', 'u', 'h', '3251', 'l', '681', 'y', 'n', 'r', '1699', '1379', '8987', '6955', 'x', 'p', 'x', '553', 'q', '5679', 'q', 'w', '9007', 'r', '8945', '7351', 'a', 'v', 'k', '1309', 'v', 'i', '4161', 'a', 'q', '2919', '6917', '6845']

Answer: a, f, h, i, j, k, l, n, p, q, r, u, v, w, x, y


Question: ['2697', 's', '8733', 'n', '5871', 'f']

Answer: f, n, s


Question: ['b', '4651', '7823', 'y', '4525', '7675', '9485', 'w', '1951', '7099', 'x', 'x', 'g', '9065', '4369', '5329', '3057', '4169', '4897', '551', '7465', 'b', 'n', '5153', '2807', '3723', 'o', '2371', '9049', 'j']

Answer:
b, g, j, n, o, w, x, y