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: ['c', '4881', '6893', '3729', 'j', '2385', 'q', 'v']

A: c, j, q, v
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Q: ['e', 'z', '5199', 'x']

A: e, x, z
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Q: ['x', 'b', '7091', '521', '9981', 'e', 'j', '2723', 'v', '7877', 'z', 'o', 'b']

A:
b, e, j, o, v, x, z
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