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: ['z', 'm', 'n', 'u', '9159', '7931', '5401', '1383', '8195', 't', 'x', 'q', 'r', '2535', 's', 'j', 'c', '8123', '2429', '5581', 'k', 'c', 't', 'i', 'm', 'o', 't', 'q', '4819', 't', '1649', 'r', 'y', 'z', '8813', '7451', '199', 'o', 'x', 's', 's', '6747']

Answer: c, i, j, k, m, n, o, q, r, s, t, u, x, y, z


Question: ['4455', 'u', '5475', '9339', '4295', 'j', '4273', '2149', 'v', '3175', '2699', '8367', '6791', 's', 'e', '2045', '5245', 'f', 'j', 'o', 'o', 'k', 'y', '4569', '9333', '1743', 's', 'a', '8355', '1627']

Answer:
a, e, f, j, k, o, s, u, v, y