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:
['1449', 'a', '6261', '303', '4651', 'n', 'u', '1595']

Ex Output:
a, n, u


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:
['3421', 'a', '8315', '7357', '9487', 'd', 'p', '3681', '8757', 'i', 'o', 'v', '597', 'h', '927', '401', '8993', '1517', 'h', 't', 'q', '1493', 'v', '653', '9863', '4181', 'v', '2249']

Ex Output:

a, d, h, i, o, p, q, t, v