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: ['7417', '2597', '2633', '7721', 'v', 'l', 'p', '4389', 'l', '3965', '6279', 'm', 'v', 'o', 'd', 'o', 'h', 'd', 'r', 'e', '8993', '2711', 'o', 'q', '1399', 'i']

Answer: d, e, h, i, l, m, o, p, q, r, v


Question: ['v', '2989', 'z', '7843', 'e', '9923', 'y', 'b', '7611', 'u', 'u', '6227', '3145', 'w', '6451', 'g', '3129', 'o', 'r', 'z', '8349', 'u', 'h', 'd', 'g', 'a']

Answer: a, b, d, e, g, h, o, r, u, v, w, y, z


Question: ['2473', '1675', 'c', '7963', '8691', 'e', '8957', 'n', 'n', '907', '5963', 'c', '6277', '7303', '383', 'v', 'n', 's', '3947', 'v', '9543', 'h', '4997', 'e', '1199', '3619', 'w', '9797', 'i', 'u', 'z', 'c', '8325', '2933', 'o', '6367', 'x', 'h', 'n', 'x', '2337', '7681', 'o', '2757']

Answer:
c, e, h, i, n, o, s, u, v, w, x, z