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: ['z', '2519', '4799', '4715', '7165', 'r', 'r', 'l', 'n', '6925', '8935', '9795', '5489', 'v', 'u', '6527', '2241', 'u', 'c', 'w', '9755', 'w', '9823', 'g']

Answer: c, g, l, n, r, u, v, w, z


Question: ['3395', '7471', 'n', '9537', '1255', '1997', '3085', '4863', '9797', '4275', 'k', 'f', '8973', '3939', 'p', 'q', '4977', '6231', '8745']

Answer: f, k, n, p, q


Question: ['g', '5987', 'x', 'l', '5947', 'e', '8183', '5027', 'd', 't', 't', '1535', '9619', '651', 'p', '6283', '9957', '2435', 'w', '7055', '6915']

Answer:
d, e, g, l, p, t, w, x