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: ['k', 'c', 'i']

Answer: c, i, k


Question: ['747', '5385', '5313', 'p', '9581', 'r', '1339', '3919', 'e', 'e', '8057', '7739', 'i', 'e', '3311', '963', 'g', 'h', '7349', 'y', '1493', 'e', '3055']

Answer: e, g, h, i, p, r, y


Question: ['s', 'f', 's', 'b', 'b', '1479', 'r', '4277', 's', '7729', 'j', '8405']

Answer:
b, f, j, r, s