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: ['2247', 'w', 'h', '4675', '6153', 'f', '6029', 'o', 'd', 'j', 'z', 'y', 'i', '6899', '3917', 'u', '6447', '6405', 'a', '1705', '8585', 'v', 'f', 'r']

Answer: a, d, f, h, i, j, o, r, u, v, w, y, z


Question: ['3611', '6825', 'j', 'e', 'r', 'a', '8889', 'y', 'x', 'k', '2651', '4545', '2289', 'r', 'q', '3163', 'a', 'i', 'j', 't', 'b', '2673', '4307', 'q', '5839', 'w', 'g', '6221', 'g', 'h', 'h', '5815', 'n', '3551', '7709', 'z', '2281', '7987', 'w', 'a', '2319', '3337', '3409']

Answer: a, b, e, g, h, i, j, k, n, q, r, t, w, x, y, z


Question: ['g', 'z', '43', 'b', '5059', '7807', '6417', '2341', '5771', '185', 'i', 'c', 'g', '2455', '4373', 'l', 'c', '229', 'u', '5773']

Answer:
b, c, g, i, l, u, z