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: ['3307', 'r', '2665', '3453', 'f', 'd', 'v', '3801', '3153', '3137', 'y', 'i', '9681', 'k', '9253', 'y', 'i', '8631', '2375', '5131', 'r', 'z', '8645', '595', 's', '6749', '2665', '709', '8203']

Answer: d, f, i, k, r, s, v, y, z


Question: ['9025', '3259', '4863', 'u', '6443', '9931', '627', 'x']

Answer: u, x


Question: ['2965', 'c', 'r', 'w', 'f', 'u', 'k', 'c', '4917', '7599', '3053', '9931', 'n', '3217', 'j', 'a', 'c', 't', '8927', '3771', '6533', '6231', '6711']

Answer:
a, c, f, j, k, n, r, t, u, w