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: ['587', '3903', 'z', 'l', 'k', '5693', 'x', '1695', 'c', '3185', 'g', '9491', '8185', '1285', '2533', '6825', '3187', '6039', 'e', '251', 'w', '7741', '9573']

Answer: c, e, g, k, l, w, x, z


Question: ['n', '9571', '2983', '7597', 'v', 'y', '1993', '1403', '8309', '7043', 'c', '7329', 'p', '4479', 'p']

Answer: c, n, p, v, y


Question: ['5499', 'm', '327', 'h', '5765', '4231', 'y', 'g', 's', '883', '9843', '2751', '8967', 'z', '2301', 'l', 'l', 'k', '7843', '7221', '3643', 'k', '5951', 'r', '9441', '235', '3835', 'l', 'e', 'y', '4061', 'l', '1177']

Answer:
e, g, h, k, l, m, r, s, y, z