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: ['7677', '4069', 'b', 'w', '4381', 'b', '5757', '711', '765', '8347', '6547', '9527', '945', '5333']

Answer: b, w


Question: ['3627', '2051', '3203', 'c', 'r', 'a', '1453', 'e', 'z', 't', '1093', '4651', 'a', 'f', '8159', '9623', 'l', 't', 'r', '6963', '7071', '8103', '3493', 'y', '2369', '609', '2011', 'f', '187', 'f', 'c']

Answer: a, c, e, f, l, r, t, y, z


Question: ['5797', 'b', 'a', '2345', 'l', '3371', '7443', '3131', 'b', '3911', '8923', 'k', '4497', 'v', '9349', '2531', 'e', '3967', 'g', 'r', '2571', '3009', 'q', '4111', 'i', 'n', 'j', '7459', 'y', 'c', '1529', '3911', 'a', 'u', 'u']

Answer:
a, b, c, e, g, i, j, k, l, n, q, r, u, v, y