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: ['x', 'b', '1467', 'y', '2101', 'y', 'm', '2745', 'z', '429', '7523', 'e', 'f']

A: b, e, f, m, x, y, z
****
Q: ['t', 'x', '1699', '8727']

A: t, x
****
Q: ['e', 'y', 'b', '5795', 'l', 'e', '729', 'f', '4741', '991', '733', '5947', '7193', 'h', '3085', '5111', '1487', 'u', 'x', 'm']

A:
b, e, f, h, l, m, u, x, y
****