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: ['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: ['u', 'd', '4193', '5687', 'p', 'r', '7787', 't']

Answer: d, p, r, t, u


Question: ['495', 'd', 'r', 'v', 'n', 'v', '8133', '837', 'b', '4495', 'k', 'x', '1735', 'h', '1579', 'd', 'v', 'f', '2375', '3297', '7607', '4859', 'k', '9661', 'v', 'd', '1309', 'q']

Answer:
b, d, f, h, k, n, q, r, v, x