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.

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

Ex Output:
b, c, e, f


Ex Input:
['s', 'w', '8949', '4025']

Ex Output:
s, w


Ex Input:
['913', 'r', 'a', '4319', '6909', '9061', 'a', 'g', 'f', 'j', 'w']

Ex Output:

a, f, g, j, r, w