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: ['2181', '7019', 'l', 'z', 'z', 'y', '1245', '4179', '6951', '7249', '2723']

Answer: l, y, z


Question: ['f', '9203', 'w', 'f', '3751', '8095', '1319', 'f', '3017', 'r', 'y', '8221', '2715', '9959']

Answer: f, r, w, y


Question: ['3353', 'w', '6047', 'l', 'a', 'p', 't', 't', 'f', 'y', 'l', 'b', '495', 'd', 'q', 'd', 'f', '3029', '3731', '2277', '2833', '9961', 'c', 'm', '3993', '7395', '1413', 't', '8999', '5771']

Answer:
a, b, c, d, f, l, m, p, q, t, w, y