Detailed 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.
Q: ['k', 'h', 'b', 't', 'p', '6381', '1717', '4785', '2197', '6467', '1369', '9019', 'b', 'h', 'i', '2579', 'x', 'i', '9403', 'p', '3095', '3287', '5857', '3117']
A:
b, h, i, k, p, t, x