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: ['7823', '2933', 'k', '4139', '5585', 'f', 'c', 'm', '2035', 'q', 'z', 'l', '1999', 'q', 'p', '7291', '2091', 'v', '423', 'e', 's', '6089', '4763', '6739']

Answer: c, e, f, k, l, m, p, q, s, v, z


Question: ['8451', 'x', '9965', '9303', 'm', 'f', '4205', 'y', 'n', '8521', '9995', 'z', 's', '3519', 'k', 'e', 'o', 'k', '9611', 'q', 'l', 'p', '3339', '4023', 'n', 'd', '8903', 'a', 'k', 'u', '4009', 'e', 'm', '989', '4495']

Answer: a, d, e, f, k, l, m, n, o, p, q, s, u, x, y, z


Question: ['9531', 'l', 'b', '9577', '5767', '2873', '5137', '8683', '3767', 'k', '3175', '8947', '5671', 'c', 'w', '5967', '9975', '1927', '6171', '607', '9927', 'b', '7317', 'o', 'e', '7613', '9523', '6875', 'q', '321', '5785', '5395', 'p', 'r', 'r', 'x', 'l', '3437', '4607', '8071']

Answer:
b, c, e, k, l, o, p, q, r, w, x