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: ['k', '8917', '3773', '6723', 'r', 'z', '3265', 'o', 'f', 'q', '9343', 'f', '1925', 'u', 'b', 'o', '5275', 'b', 'n', 'd', 'j', '4825']

Answer: b, d, f, j, k, n, o, q, r, u, z


Question: ['8381', 'j', '761', '5431', '7601', 'd', '4339', '1479', 'b', 'x', 'f', 'w', '2437', '7725', '6385', '411', 'w', 'w', 'i', '2769', '5709', '5703', 'k', '5301', '6503', '7833', 'y', '3813', '7061', '5531', 'n', '2251', 'y', '8941', '8481', 's', 't', 't', '3345', 'k', '1545']

Answer: b, d, f, i, j, k, n, s, t, w, x, y


Question: ['h', '6779', '9887', '1', 'q', '1869', 'n', '5775', '1401', '4985', 'v', '7441', '4995', 't', '1529', 'm', '3109', 'x', '7355']

Answer:
h, m, n, q, t, v, x