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: ['7055', '2573', '1713', 'x', 'm']

Answer: m, x


Question: ['d', 'p', 'q', '5319', 'w', '4887', '6695', 't', '7711', 'l', '7597', 's', 'n', '1461', 'e', '9045', '1307', 'j']

Answer: d, e, j, l, n, p, q, s, t, w


Question: ['2021', 'h', '711', 'r', 'r', '9285']

Answer:
h, r