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', 's', 'z', 'v', '5401', 'u', '8859', 'i', 'l', 'a', 'p', 'v', 'v', 'o', '3969', '4091', 'y', '6827', '1799', '5163', 'd', 'w', '4795', '5167', 'x', 'q', '2903', '1171', '5279', '449', '7901', 'u']

Answer: a, d, i, j, l, o, p, q, s, u, v, w, x, y, z


Question: ['f', '7573', '2067', 'n', '3671', '7969', '7889', '4893', '6501', 'l', 'y', '4331', 'a', 'e', '2081', '3863', 't', 'j', '7921', 's', '7203', '7797', 'f', '4279', '1299', '987', '5003', '9071', '9559', '6061', '1889', '2653', 'm', 'w', '665', '7343', '9763', 'r', '6343', '9393', '9289']

Answer: a, e, f, j, l, m, n, r, s, t, w, y


Question: ['c', 's', '4487', '1453', '203', 'r', 'r', 's', 'q', 'u', '2421', '7955', '7399', 'n', 'm', '2945']

Answer:
c, m, n, q, r, s, u