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: ['1233', '405', '8901', '7147', '8841', 's', 'v', '3131', 'p', 'd', 'y', '5873', '439']

Answer: d, p, s, v, y


Question: ['w', '491', 'x', 'u', 'z', 'q', '5411', '7629', '8261', '8629', '1441', '5139', 's', 'm', '6463', 'u', 'z']

Answer: m, q, s, u, w, x, z


Question: ['n', 't', 'n', '5153', 'l', '2473', '9829', 'k', '5875']

Answer:
k, l, n, t