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: ['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: ['q', '8149', '4087', '5183', 't', 'j', 'e', 'g', 'r', '2125', 'y', 'l', 'g', '3673', 's', 'r', 'e', 'v', '4259', 'v', '3477', '9353', '3639', 'v', 'n', 'e', 'z', '5071', 'x', '6287', 'e', 'e']

Answer: e, g, j, l, n, q, r, s, t, v, x, y, z


Question: ['j', '8481', 'w', '7563', 'q', '665', '8727', '5477', 'y', 'j', 'v', '8379', 'j', '9553', 'd', 'm', '2467', '6503', 'l', 'x', '8131']

Answer:
d, j, l, m, q, v, w, x, y