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:
['565', 'i', '615', '3047', 'm', '195', '7547', '3003', '9213', '9063', 'c', '5099', 'v', '5003', '9053']

Ex Output:
c, i, m, v


Ex Input:
['a', 'p', 'y', 'l', 'l']

Ex Output:
a, l, p, y


Ex Input:
['h', 'k', '1579', '5571', '8309', '6667']

Ex Output:

h, k