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:
['r', 'n', '7583', '8697', '7927', 'l', '5003', '1363', 'p', 'e', 'q', '6227', '6915', '8619', '9011', 'n', '3063', '3799']

Ex Output:
e, l, n, p, q, r


Ex Input:
['8975', '7199']

Ex Output:
-1


Ex Input:
['l', '7667', '2425', '2347', 'd', 'b', 'j', 'g', '2873', '4901', '5011', 'n', 'h', 'v', '1205', '4403', 'x', '921', 'w', '8651', '2221']

Ex Output:

b, d, g, h, j, l, n, v, w, x