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: ['i', 's']

Answer: i, s


Question: ['h', 'u', 'y', '7677', '9441', '1769', 'v', '1433', 'l', '7739', 'a', '8305', 'n', 'a', '6711', '3161', 'e', 'u', '993', '2211', '4011', 'q', 'o']

Answer: a, e, h, l, n, o, q, u, v, y


Question: ['5675', '7121', '7607', 'm', 's', 'z', 'x', 'c']

Answer:
c, m, s, x, z