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: ['u', 'w', '401', 't', 'g', 'h', 'g', '8073', '9597', '1347', '7835', '5007', '977', 'p', '7679', 'b', '4883', '4931', '999', 'r', '1181', 'x', '2063', 'l', 'w', 'i', 'l', 'x', 'i', '9057', '5007', 'w', '743', '1635', 'y', 'f', '9227', 'z', '5227', 'd', '7129', 'k', '7657']

Answer: b, d, f, g, h, i, k, l, p, r, t, u, w, x, y, z


Question: ['1429', '7763', '9737', 'l', '1865', 's', '9871', 'e', 'c', 'q', '2727', 'v', 'p', 'd', 'p', '6771', 'c', '7051', 'e', 'b', 'd', 'o', '7427', 'x', 'e', 'm', 'u', '4887', '1649', 'u', 'h', '5249', 'e', '7579', '8549']

Answer: b, c, d, e, h, l, m, o, p, q, s, u, v, x


Question: ['8627', '3263', '9009', '3631', '847', 'y', '8981', 'r', 'y', '5495', 'p', '4251', 'e', 'n', '7985', 'l', 'l', '4405', 'i', 'z', '5303', 'l', '8575', 'g', 'r', '5123', '1303', 'r', '8677', 'h', '3105', 'j', '6403', '5617', '9387', '6581', 'w', 's', 'v', '6237']

Answer:
e, g, h, i, j, l, n, p, r, s, v, w, y, z