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: ['8311', 'w', 'f', '3431', '9863', '5817', '3969', '2705', 'x', 'm', 'k', 'z', 'z', '235', 'x', '417', 's', 'i', 'y', '8833', '8675', 's', 'm', '2149', '765', 'u', '1021', '7823', 'x', '7275', '3157', 'k']

Answer: f, i, k, m, s, u, w, x, y, z


Question: ['6463', '871', '5781', '283', '9653', 'f', '9661', '3365', '2889', '5499']

Answer: f


Question: ['y', 'w', 'x', '8645', '2119', '5917', 'p', '8691', 'y', '2499', '59', 's', '9419', '5083', '3385', '483', '7679', 'i', '6435', 'l', 'c', 'f', 'd', '535', '891', '9247', '8175', 'b', 'a', 'x', 'y', '8391', '6359', 'u', 'r', '9933', '9241', 'o', 'a', '9169', 't', '9369', '2319', 'q']

Answer:
a, b, c, d, f, i, l, o, p, q, r, s, t, u, w, x, y