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:
['k', 'v', 'e', '6377', 'y', '3585', '4535', 'f', 'g', 'm', 'f', '8369', 'v', '7445', '4527', '9383', 'n']

Ex Output:
e, f, g, k, m, n, v, y


Ex Input:
['9925', 'f', '6149', 's', 'd', 's', '75', '8577', '2319', 'b', '3769', '5211', 'q', 'm', '8127', 'f', '3801']

Ex Output:
b, d, f, m, q, s


Ex Input:
['f', 'j', '6361', 'o', '1251', '3471']

Ex Output:

f, j, o