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:
['w', '5341', 'b', '6243', 'v', '877', '1087', '6763', '5241', '3369', '9119', 't', 'v', 'j', '8261', 'o', 'b']

Ex Output:
b, j, o, t, v, w


Ex Input:
['w', '8777', 'y', 'e', '8015', 't', 'w', '53', '9149', 'e', 'k', '1837', 'b', 's', '4007', '4905']

Ex Output:
b, e, k, s, t, w, y


Ex Input:
['9917', '299', '5889', 'w', 'a', 'q', '231', '8007', '3267', '8663']

Ex Output:

a, q, w