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:
['d', 'a', '6931', 'c', 'u', 'z', '9713', 'v', 'm', 'e', 'k', 'o', '9705', 'a', '5373', 'c', '2983', '8097', 'h', '3039', 'g', 'f', 'n', 'v', '853', '8227', '7573', 'j', 'h', 'k', 'o', 'k', '8897', 'd', 'g', 'd', 'd', '4039']

Ex Output:
a, c, d, e, f, g, h, j, k, m, n, o, u, v, z


Ex Input:
['6027', 'v', 'b', 'l', '7853', 'r', 'y', '2919', '3831']

Ex Output:
b, l, r, v, y


Ex Input:
['w', 'i', 'd', 'n', '4949', 't', 'y', 'r', 'm', '147', 'g', '4763', 'c', '5415', 'l', 'x', 'h', '8207', '4905', '6541', 'a', '481', '6405', 'g', '7487', '1337']

Ex Output:

a, c, d, g, h, i, l, m, n, r, t, w, x, y