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: ['1197', '305', 's', '1113', 'n', '2207', 'e', '227', '2833', '607', '3049', 'v', '4615', 'a', 'k', 'r', 's', '3571', 'f', '4215', 'f', '8985', '5559', '4111', 'u', '1433', '1943', '8831', 'w', 'x', 'o', '9023', 'u', 'y', 'p', 's', 'h', '8877', 'p', 'n', '8903', '5811']

Answer: a, e, f, h, k, n, o, p, r, s, u, v, w, x, y


Question: ['1749', 'i', 'w', 'j', '3171', '1999', '1037', '4937', '7013', '3593', '287', 'o', 'i', 'j']

Answer: i, j, o, w


Question: ['3247', '1533', 'y', '7335', 'd', 'j', 'e', 'e', 'o', 'e', '6699', '2489', 'u', 'n', 'v', 'q', '1887', '6919', '2081', 'c', 'p', 'v', 'g', '8859', 'a', '8815', '517', '8825', 'm', '333', 'f', 'h', 'x', '1799', '4053', '1869', '2633', 'k']

Answer:
a, c, d, e, f, g, h, j, k, m, n, o, p, q, u, v, x, y