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: ['3395', '7471', 'n', '9537', '1255', '1997', '3085', '4863', '9797', '4275', 'k', 'f', '8973', '3939', 'p', 'q', '4977', '6231', '8745']

Answer: f, k, n, p, q


Question: ['d', 'g', '9019', '9987', '8713', '9513', 'a', '2043', 'd', '5817', 'w', 'd']

Answer: a, d, g, w


Question: ['1189', '7143', '993', '1513', '6449', '9749', '5963', '8159', 't', '3543', 'j', 'i', '4227', '1463', '6431', '4987', 'y', 'q', 'f', '321', 'm', 'r']

Answer:
f, i, j, m, q, r, t, y