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: ['2527', '9123', '8717']

A: -1
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Q: ['i', '4447', 'g', 'o', 'j', 'p', 'l', 'q', 'o', '8777', 'r', 'v', '961', '6083']

A: g, i, j, l, o, p, q, r, v
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Q: ['m', 'z', '5323', 'g', '595', '4927', '7925', '4469', 'i', '871', 'v', '525', 'o']

A:
g, i, m, o, v, z
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