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: ['1345', 'y', '7221', 'h', 'r', '3255', 'k', 'r', 'j', '8639', '467', 'f', 'k', 'n', 'k', 'j', 'l', 'w', '143', 'w', 'q', '5657', '589']

Answer: f, h, j, k, l, n, q, r, w, y


Question: ['w', '743', '5757', '8731', 'k', 'p', '317', 'n', 'x', '5649', 'l', 'm', 'c', '2499', 'l']

Answer: c, k, l, m, n, p, w, x


Question: ['c', '7603', '347', 'f', '603', '6889', '411', 'e', '1857', '3235', '3405', 's', '2107', 'd', 'n', 'p', 'u', 'd', 'd', '5029', 'u', 'g', '8285', '1827', '4991', '8017']

Answer:
c, d, e, f, g, n, p, s, u