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: ['8815', 'w', '8629', 'y', '3891']

Answer: w, y


Question: ['9627', '9879', '5421', '4755', '1533', '6727', 't', '7641', 'd', '3929', 'h', '3989', '8441', 'k', 'p', '2653', 'm', 'b', 'i', '3431', '4907', '5687', 'g', 'h', '9185', '5051', 'k', '7135', '709']

Answer: b, d, g, h, i, k, m, p, t


Question: ['s', '6741', 't', '7523', '1221', '2625', 'w', '105', '7267']

Answer:
s, t, w