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', '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: ['p', '6123', '6961', 't', 'p', 'h', '9035', 'r', '6341', 'x', '3635', '5885', 't', '3543', '9567', '1787', 'o', '2991', 'k', '3441', '4091', 'a', 'r', '423', '9383', '7147', 'h', '663', 'd']

Answer: a, d, h, k, o, p, r, t, x


Question: ['i', 'z', 'k', '9255', 'o', 'i', '9849', '5219', 'x', 'i', 'x', '5485', '2041', '3769', '4215', '5125', '8911', 'g', '907', 'g', 's', 'n', '1449', '2075', 'w', 't', '6013', 'm', '5209', '8817', 'o', 'r', 'l', 'm', '7815', 'q', 'm']

Answer:
g, i, k, l, m, n, o, q, r, s, t, w, x, z