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: ['2393', 'c', '4413', '5529', '1487', '2499', 'i', 's', 'i', '8575', 'm', 'z', '7179', '6637', '9181', 'z', 'h', '2487', 'i', '3779', '2017', '5217', '5013']

Answer: c, h, i, m, s, z


Question: ['4993', '6641', '3127', '9409', '8453', '5909', '6109', 'y', 'f', '6859', 'c', '3863', 't', '1221', '3689', 'w', 'h', '7947', 't', '5979', 'l', 'i', '1321', '3149', 'l', 'v', '3825', 'z', '9297', 'f', 'e', '7205', 'a', 'a', '2645', '391', '4965', 'w', 'h', '7715', '9409', '3603', '4147']

Answer: a, c, e, f, h, i, l, t, v, w, y, z


Question: ['r', 'y', 'c', '3211', '9245', '8459', '8521', '5781', 'w', 's', 'd', '5299', 'a', 'y', 'g', 'm', '6435', '8605', 'e', 'h', '6871', 's', '387', 'l', '5829', 'e', 'd', '9545', '2945', 'k', 'v', 't', '8449', '2199', 'm', '2599', '1489', '6623', 'x', 'l']

Answer:
a, c, d, e, g, h, k, l, m, r, s, t, v, w, x, y