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.

Q: ['1367', 'h', '4153', '1587', 'h', 'b', 'n', 'u', 'n']

A: b, h, n, u
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Q: ['d', '1625']

A: d
****
Q: ['q', 'i', 'y', '8837', '4113', '9049', '4471', '6931', 'g']

A:
g, i, q, y
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