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:
['u', 'i', '1185', '3795', '5417', 'k', 'b', '2629', '2635', 'z']

Ex Output:
b, i, k, u, z


Ex Input:
['t', 't', 'p', '3245', 'x', 'g', 'i', 'u', '2599', '8613', 't', 'v', 'p', '5635', 'y', '9567', '5193', '8617', 'q', 'f']

Ex Output:
f, g, i, p, q, t, u, v, x, y


Ex Input:
['d', 'g', 'n', 'r', 'l', 'a', '9229', '3257', 'p', 'c']

Ex Output:

a, c, d, g, l, n, p, r