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: ['e', 'z', '5199', 'x']

Answer: e, x, z


Question: ['x', 'i', 'r', '6011', 't', 'f', 'b', 'i', '8367', '4051', '1459', 'f', '5583', '9609', 'l', 'q', 'g', '8443', 'o', '8697', '7053', '8325', 'k', '7021', 'q', 'm', '6899', '9981', '8985', 'i', 'j', '8043', 'k', '535', '7603', '7629', 'k', '2779', 'g', '2049', 'x', 'd', '8527', 'k', 'q']

Answer: b, d, f, g, i, j, k, l, m, o, q, r, t, x


Question: ['5629', 'g', 's', 't', '9339', 'h', '9901', 'r', '1377', '8245', '2423', '1709', '4243', 'w', '8529', '5541', '8815', 's', 'i', '809']

Answer:
g, h, i, r, s, t, w