Instructions: 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.
Input: ['h', '8431', 'c', 'g', 'c', '8391', '9385', '7529', 't', 'x', '6033', '3579', '6905', '445', 'i', '2707', '4327', '7533', '7381', '1677', '8859', 'a', 'f', 'n', '5127', 'l', '7407', 'f', '5591', 'b', '4109', '6367', 'h', '1045', '7841', '7785', 'v']
Output:
a, b, c, f, g, h, i, l, n, t, v, x