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', '6595', '1595', 'v', 'h', 'b', '8815', '6681', 'j', '7581', 'p', '9095', '5453', 'r', 'y', '7755', 'x', '1853', 'k', 'q', 'u', 'j', 'q', '9651', 'o']

Answer: b, h, j, k, o, p, q, r, u, v, x, y


Question: ['7055', '2573', '1713', 'x', 'm']

Answer: m, x


Question: ['9483', 'b', '7917', 'j', '9887', '3863', 'u', 'o', 'c', 'c', '2959', 'a', '7883', '3971']

Answer:
a, b, c, j, o, u