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:
['k', 'z', '303', 'a', 'f', 'q', 'i', '1475', '3453', 'd', 'w', '4037', 'z', 'h', 'k', '3547', '1561']

Ex Output:
a, d, f, h, i, k, q, w, z


Ex Input:
['9403', '9881', '8391', 't', '1793', 'w', 'x', 'y', '6383', 'j', 'r', '5323', 'r', 'l', 'e', 'u', '7193', '2309', '837', 'z', 'w', 'n', '4427', '8269', '6333', 'a', 'p', '1933', '8497', '2665', '1349', '6807', '9009', 'b']

Ex Output:
a, b, e, j, l, n, p, r, t, u, w, x, y, z


Ex Input:
['7045', '7145', 'm', '6919', '507', '3183', 'o', 'd', 'c', '3095', '2593', '3547', 'h', 'i', 'r', '9615', '5525', '5009', '1633', 'k', '147', '4917', 'b', '3275', '5675', '8533', 'j']

Ex Output:

b, c, d, h, i, j, k, m, o, r