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

Answer: i, j, o, w


Question: ['s', 's', '3619', '6051', 'h', '213', '3937', 'v', 'p', 'y', '8449', '9337', '5327', 'a', 'a', 'w', '3985', 'n', 'm']

Answer: a, h, m, n, p, s, v, w, y


Question: ['f', '63', '231', '6751', 'z', 'c', 'e', 'z', 'n', '8619', 'w', 'f', 'v', 'k', '335', 'r', 'z', '1323', 'q', '9713', '7991', 'w', 'l', '3491', 'q', 't', 'r', '2401', 'j']

Answer:
c, e, f, j, k, l, n, q, r, t, v, w, z