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:
['2161', '8009', '3057', 'r', '3897', 'd', 'j', '2727', 'b', '3231', 'i', '9227', '393', '5799']

Ex Output:
b, d, i, j, r


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

Ex Output:
b, c, e, f


Ex Input:
['5045', 'd', 'p', 'a', 'a', 'y', 'v', '547', '5311', '9139', 'o', '3409', '4901', '6045', 'j']

Ex Output:

a, d, j, o, p, v, y