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:
['w', 'i', '4383', '7667', '9617', 'y', 'a', '8051', 'w', '4857', 'y', '3953', 'u', 'o', 'y', 'i', '9201', 'g', '1807', '5367', 'g', '5263', '3995', '6665', '3113', '9433', '6315', 'm', '845', 'x', 'c', 'v', 'h', '1491', 'g', '3519', 'x', 'b', '7695']

Ex Output:
a, b, c, g, h, i, m, o, u, v, w, x, y


Ex Input:
['7799', '8163', '3389', 'x', 'k', 'm', '6085', 'f', '1131']

Ex Output:
f, k, m, x


Ex Input:
['169', '5553', 'v', '5997', '2179', '8445', '7937', '3051', '9017', '567', 'r', 'e', '7549', 'c', 's', '9335', 'l', '1103', '2469', '8903', 'd']

Ex Output:

c, d, e, l, r, s, v