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: ['i', 'h', '8299', 'e', 'c', '5543', '5241', 'f', '3985', 'f', 'z', '1245', 'e', 't', 'g', '5199', '9217', 'q', 'j', 'p', '767', 'z', '1803', 'k', '7303', '3187', '2507', '6471', '3337', '6037', '9291', 'a', 'l']

Answer: a, c, e, f, g, h, i, j, k, l, p, q, t, z


Question: ['4009', 'y', '9077', 'p', 'q', '6711', '6443', '5491']

Answer: p, q, y


Question: ['8291', '1901', 'd', '1341', '5401', 'x', '8827', 'r', 'm', '1137', '7051', 'i', 'k', '5375', '9977', 'k', '4035', '5761', '5745', '9603', 's', '2033', 'b', '7337', 'r', 'h', 'o', 's', '8787', 'j', 'k', '3143', 'z', '8481', '2613']

Answer:
b, d, h, i, j, k, m, o, r, s, x, z