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: ['2161', '8009', '3057', 'r', '3897', 'd', 'j', '2727', 'b', '3231', 'i', '9227', '393', '5799']

Answer: b, d, i, j, r


Question: ['1449', 'a', '6261', '303', '4651', 'n', 'u', '1595']

Answer: a, n, u


Question: ['2543', '6431', '4375', '677', '5565', '749', '3225', 't', 'z', '2819', 'o', '6857', '8743', 'q', 'j', '5043', '6143', 'p', '5301', 'q', '9425', 'o']

Answer:
j, o, p, q, t, z