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: ['5039', '2227', 't', 'o', '3313', 'm', 'v', '637', '6773', 'v', 'c', 'l', 'y', 'u', '3823', '9669', 'k', 'h', '3589', 'b', 'i', '3833', 's', 'm', '8201', 'u', '3143', 'k', '4111', '9769', '425', '4339', '209', 'c', 'c', '669', '8201', 'u', '7443', '2387', '6919', 'b', 'b', '2873']

Answer: b, c, h, i, k, l, m, o, s, t, u, v, y


Question: ['i', '9215', 'n', 'p', '4815', '8757', 'm', '1755', 'c', 'z']

Answer: c, i, m, n, p, z


Question: ['x', 'h', '6279', 'i', '7889', '3049', '421', '7491', '2399', '6113', '6967', 'v', 'z', 'c', 'b', '4475', '3775', '6669', '5419', 'v', '5765', 'a', 'q', 'e', '7779', '5155', 'a', 'g', 'f', 'o', 'v', '4517', '7643', 'm']

Answer:
a, b, c, e, f, g, h, i, m, o, q, v, x, z