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:
['c', '8389', 'j', '6113', '5843', 'f']

Ex Output:
c, f, j


Ex Input:
['7677', '4069', 'b', 'w', '4381', 'b', '5757', '711', '765', '8347', '6547', '9527', '945', '5333']

Ex Output:
b, w


Ex Input:
['6335', '6767', '1399', '3927', 'k', 'b', 'l', '1515', '4935', '6145', 't', 'w', '9419', 'z', '8103', '4115', '8427', 'o', 'k', '3471', 'n', '855', 'b']

Ex Output:

b, k, l, n, o, t, w, z