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:
['3395', '7471', 'n', '9537', '1255', '1997', '3085', '4863', '9797', '4275', 'k', 'f', '8973', '3939', 'p', 'q', '4977', '6231', '8745']

Ex Output:
f, k, n, p, q


Ex Input:
['8281', '4831', '1329', 'g', 'e', '8879', 'n', 's', 'x', 'j', '6305', 'j', '921', '3677', '5107', 'n', 'j', '9285', 'a', '5329', '6671', 'c', '9283', 'l', 'a', '7907', 'q', '7605', '855', '6477']

Ex Output:
a, c, e, g, j, l, n, q, s, x


Ex Input:
['n', '1603', 'z', 'b', '511', '3707', 'y', 'y', 'o', '9215', '6421', 'e', '611', '307', 'k', '3415', '7231', 'w', '7559', '8461', '4445', 'p']

Ex Output:

b, e, k, n, o, p, w, y, z