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: ['4269', '1847', '2025', '601', 'g', 'n', 'h', '3499', '4977', '3579', '9355', '3489', 'm', 'm', '4401', '4605', 'l', '3977', 'h', 'd', 't', '5135', '7787', 'k', 'q', '7699', '5325', '6269', '1865', 'h', '8915', '5677', 'g', '603', '1435']

Answer: d, g, h, k, l, m, n, q, t


Question: ['g', 'u', 'q', '1375', '9491', 't', 'w', 'c', 'v', 'y', '3169', '1607']

Answer: c, g, q, t, u, v, w, y


Question: ['7623', 'w', 'u', 'g', 'y', 'y', '5795', 't', 'e', '1599', '7413', '3335', '631', 'i', '3833', 'a', '4975', '6279', 'b']

Answer:
a, b, e, g, i, t, u, w, y