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:
['o', 'h', 'z', 'n', 'e', 'y', 't', '4371', 'm', '1059', '4853', '8529', 'l']

Ex Output:
e, h, l, m, n, o, t, y, z


Ex Input:
['x', '4283', 'n', 'b', 'g', 'p', '8305', '7781', '5907', 's', '1305', 'w', '8623', 'o', 'c', 'u', '1839', '2869', '7537', 'y', '2395', '5309', 'e', '4059', 'l', '6647', 'p', '9717', 'y', 'y', '3769', '2527', '2981', '5255', '4063', 'j', '4843', 'j', '9355', 'z']

Ex Output:
b, c, e, g, j, l, n, o, p, s, u, w, x, y, z


Ex Input:
['6433', 'u', 'd', '9083', 't', '7641', 'a', 'r', 's', '6003', 'z', 'n', 'n', '7621', 'u']

Ex Output:

a, d, n, r, s, t, u, z