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: ['6597', '7889', 'x', 'v', 'm', 'j', 'j', 'w', 'v', '177', 'x', '8353', '5897']

Answer: j, m, v, w, x


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

Answer: b, h, n, u


Question: ['o', '543', '7297', '3879', '203', 'i', 'h', '9953', '8593', 'v', 'w', '8977', '1519', 'j', '2091', 'z', 'f', '6513']

Answer:
f, h, i, j, o, v, w, z