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: ['333', 'b', '261', 'k', 'p', '7861']

Answer: b, k, p


Question: ['5337', '4877', '9443', '3445', 'u', '2571', 't', 'n', 'x', '1985', '5145', '3397', 'p', '9259', 's', 'x', 'u', 'c', 'g', 't', 'j', '829', '8273', 'e', 'j', 'r', 'x', '865', '4773', 'h', '4407', '8591']

Answer: c, e, g, h, j, n, p, r, s, t, u, x


Question: ['395', 'b', '223', '513', 'n', '9329', '7021', 'o', '2475', 'j', 'm', '7609', 'm', '9061', '6481', 'e', '2555', '9269', 'd', '2963', 'u', '9757', 'p', '1555', '4363', 'z', 'h', '9139', 'r', 'm', 'w', 'o', 'm', '4703', 'w', 'f', '1241', '2515', 'z']

Answer:
b, d, e, f, h, j, m, n, o, p, r, u, w, z