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.
--------
Question: ['m', '3809', 'l', 'k', '1929', '7963', 'n', 'u', '2125', 'g', 'o', '8325', 'o', 'h', 'y', '3025', 'e', 'e', 'c', 'x', '8445', '4979', 'z', 'f', '4201', '4765', 'g']

Answer: c, e, f, g, h, k, l, m, n, o, u, x, y, z


Question: ['i', 'h', '8299', 'e', 'c', '5543', '5241', 'f', '3985', 'f', 'z', '1245', 'e', 't', 'g', '5199', '9217', 'q', 'j', 'p', '767', 'z', '1803', 'k', '7303', '3187', '2507', '6471', '3337', '6037', '9291', 'a', 'l']

Answer: a, c, e, f, g, h, i, j, k, l, p, q, t, z


Question: ['l', 'f', 'i', 'k', 'v', 'a', 'j', 'z', 's', '4727', '7309', 'n', '8973', '6931', '3885', '7411', 'y', '479', 's', '3943', 'k', 't', '2775', 'z', 'x', '8451']

Answer:
a, f, i, j, k, l, n, s, t, v, x, y, z