Teacher: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.
Teacher: Now, understand the problem? Solve this instance: ['k', '3617', '4435', '1497', '4535', '5263', '1315', 'g', '8205', 'f', 'v', '2659', '7603', 'f', 's', 's', '6583', 'x', '8947', 's', 'b', 'i', 'n', 'i', 'n', '7131', '3343', 'q', 'j', '5871', 'l', 'j', 'a', '2975', 'f', '1219', '2913', '5565']
Student:
a, b, f, g, i, j, k, l, n, q, s, v, x