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: ['p', 'g', 'q', 'e', '8045', '9999', '9555', '7995', '7195', 'z', 't', '5223', '3699', 'i', '4797', '3817', 'x', 'y', 'w', 'o', '8915', '7803', 'n', '1117', 'c', '9647', 'p', 'e', '9669', '4845', '9255', '4545', '3693', '6871', 'w', '4327', '3285', 'k', 'f', 'x', 'i', 'b', '5967', '6601']

Answer: b, c, e, f, g, i, k, n, o, p, q, t, w, x, y, z


Question: ['n', '7337', '6887', '2203', '4663', '2837', '6451', '959', '8027', 'p', 'v', 'q', 'g', '8059', '6151', 'v', '7097', '6583', '7637', '2367', 'w', '9603', '5365', '3773', '1707', 'k', 'x', 's', 'c', 'u', '3641', '6137', '1207', 'k', '5531', '4543']

Answer: c, g, k, n, p, q, s, u, v, w, x


Question: ['8549', 's', 's', 't', '2949', '7987', '3343', '4881', '8657', 'g', 'h', 'w', '5843', '4151', '1227', 'y', 'n', '5013', '4065', 'm', 'q', 'a', 'v', '1503', 'i', 'p', '9629']

Answer:
a, g, h, i, m, n, p, q, s, t, v, w, y