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:
['6597', '7889', 'x', 'v', 'm', 'j', 'j', 'w', 'v', '177', 'x', '8353', '5897']

Ex Output:
j, m, v, w, x


Ex Input:
['9783', '3185', '8225', 'u', '1123', 'd', '3453', 'i', '7713', '8457', '8609', 'h', '2767', 'e', '7191', '2929', '1089', '393', 'e', 'd', '11', '9329', '683', '1271']

Ex Output:
d, e, h, i, u


Ex Input:
['3147', 'i', 'e', 'r', '2309', '5221', 'o', 's', '9887', '7185', '4331', '7135', 'r', '381', 'n', '5735', 'a', '7491', 'j', 'v', 'n']

Ex Output:

a, e, i, j, n, o, r, s, v