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: ['3743', '765', '5299', '3069', '8547', '8991', '1811', 'k', '5557', '4907', '5907', 'd', 'r', 'z', '5385', '5463', 'f', '2063', 'm', '3419', 'k', '3897', '4049']

Answer: d, f, k, m, r, z


Question: ['v', 'l', 'v', '7673', '8975', 'u', '2471', '4151', '3615', '1139', 'i', 'z', '8833', 'v', '341', 'l', 'n', 'l', 'd', '9207', '1861', '3901', 'a']

Answer: a, d, i, l, n, u, v, z


Question: ['h', '5949', '2175', 'g', '8287', '5637', '6851', '5005', 'l', '7211', '9715', '2695', '6429', 'l', 'v', 'p', 'm', 'a', '3679']

Answer:
a, g, h, l, m, p, v