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.

['8315', 'b', '4333', 'f', '6507', '6211', '3475', 'c', 'e', '8039', '661']
b, c, e, f

['e', 'z', '5199', 'x']
e, x, z

['9117', '1153', 'f', 'b', '9979']

b, f