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: ['2165', 'f', '5081', 's']

Answer: f, s

Question: ['4031', 't', 'o', 'c', 'x', '3007', '8329', '6345', '1267', '1017', 'o', 'x', 'l', '4129', 'd', '1987', '487', 'o', 'g', 'j', 'v', 'x', '3983', 'f', 'g', '5759', 'k', 'i', 'o', 'b', 'n', '683', 'j', 'o', 't', '4361', 'u']

Answer: b, c, d, f, g, i, j, k, l, n, o, t, u, v, x

Question: ['763', '1407', '7737', '655', 'q', '8091', '6043', 'o', '839', '1101', 'v', 'd', '9191', '5533', 'w', '2297', '7953', 'f', '1699', 't', '8921', '9529', '7417', '6519', 'p', '9917', '3397', '3501', '8927', 'o', 'i', '3119', '2501', '9999', '5453', '6341', '541', 'e', '3287', 'k', 'k', 'c', '661', 'p']

Answer:
c, d, e, f, i, k, o, p, q, t, v, w