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: ['n', 'q', '6461', 's', '8565', '2237', '2071', '8143', '2977', '5511', 'j', 'o', '5793', 'j', 'm', 'n', '8031', 'j', '535', '5001', 's', 'y', '1737']

Answer: j, m, n, o, q, s, y


Question: ['j', '6675', 'u', 's', '705', '8227', 'f', 'w', 'n']

Answer: f, j, n, s, u, w


Question: ['7343', '5005', '2077', '9413', '5641', '6073', 'k', 'r', '6465']

Answer:
k, r