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:
['8815', 'w', '8629', 'y', '3891']

Ex Output:
w, y


Ex Input:
['x', 'b', '1467', 'y', '2101', 'y', 'm', '2745', 'z', '429', '7523', 'e', 'f']

Ex Output:
b, e, f, m, x, y, z


Ex Input:
['6111', 'n', '6173', 'q', '2443', '5421', '755', 'w', '5577', 'x', 'p', 'h', '6867', '787', 'k', 'l', '4499', 'j', 'w', 'a', '6027', '4385', 'o', 'i', 'r', '235', '2189', '2589', '8927', 'p', '9603', 'k', 'h', '7887', '2541', '5981', '2063', 'd']

Ex Output:

a, d, h, i, j, k, l, n, o, p, q, r, w, x