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: ['n', 'w', '6735', '3427', '6115', 'q', '7851', '3645', 'g', '6825', '6515', '4885', 'z']

Answer: g, n, q, w, z


Question: ['4927', 'h', 'x', '4719', 'j', 'f', '7797', 'l', 'i', 'q', 'x', 'i', 'k', '3215', 'k', '1625', 'g', 't', 'i', 'w', 'n', '6659', '8355', '831', 'h', '9723']

Answer: f, g, h, i, j, k, l, n, q, t, w, x


Question: ['2493', 't', '5189', '8085', 'y', 't', 't', '625', '9537', '549', '7753', 'z', 't', '259', 'v', 'q', 't', '515', '8999', '3399', '9301', '4187']

Answer:
q, t, v, y, z