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: ['c', '8389', 'j', '6113', '5843', 'f']

Answer: c, f, j


Question: ['k', 'r', 'f', '4369', 'z', 'z', 'l', '143', 'r', '707', '9167', 'g', '1749', 'i']

Answer: f, g, i, k, l, r, z


Question: ['2599', '5429', 'y', 'm', '3835', 'w', 't', '3159', 'm', '2503']

Answer:
m, t, w, y