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: ['c', 'h', '8655', 'r', '7531', 's', 'r', 'w', 'e', 's', 'p', '1709', '5447', 'b', '5855', 'w', 'f', 'i', '7809', 'q', '1975', 'z', '4037', 'k', 'l', 'z', 'g', '9739', '8801', '3405', '6549', '4561', 'd', '1669']

Answer: b, c, d, e, f, g, h, i, k, l, p, q, r, s, w, z


Question: ['t', 'm', '7071', 'j', '353', 'n', 'a', 'm', '9211', 'i', '9537', 'q', '7669', '869', '8753', '8071', '375', '9971', 'c', 'n', '5851', 'u', '2491', '2697', '2789', '4683', '879', 'q', 'g', 'p', 'd', 'x', 'r', 'i', '8171', '5449', '2477', '1151', 'z', '3845', '1079', 'j', 'n', 'p', '8199']

Answer: a, c, d, g, i, j, m, n, p, q, r, t, u, x, z


Question: ['r', '9693', 'e', '7547', 'k', 'd', '2917', 'e', 'p', '8117', '1641', 'u', '3681', 'x', 'e', 'e', '2305', 'e', 'y', 'c', 'h', 'q', '4809', 'n', 'n', '3257', '4939', '7947', 'f', 'h', '8827', '4491', 'd', 'd', '6469', 'x', '7733', 'c', '3219', '777', 'd', 'p']

Answer:
c, d, e, f, h, k, n, p, q, r, u, x, y