Q: 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.
['9141', 'c', 'p', '1537', 'k', '8955', '4857', '4845', '8013', 'o', 'p', '8377', '709', 'g', 'z', 'f', '7035', '8675', '6017', 'x', '2491', 'q', 'p', 'o', '3991', 't', 'i', 'c', '2377', '5905', 'g', '6671', 'g', '4431', '3823', 'y', 'n', '6309', '7857', '2017']
A:
c, f, g, i, k, n, o, p, q, t, x, y, z