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:
['b', 'd', '8153', 'u', '3695', '5317']

Ex Output:
b, d, u


Ex Input:
['v', '3765', '4065', 'a', '4201', 'f', 'x', '9275', 'q', '9303']

Ex Output:
a, f, q, v, x


Ex Input:
['l', '959', 'p', '7433', '8125', '8737', 'b', 'c', 'j', 'a', '453', 'q', '2117', 'k', 'q', 'p']

Ex Output:

a, b, c, j, k, l, p, q