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:
['a', '7599', 'i', '9455', '3955', '2015', 'j', '7345', 'x', 't', 'c', '1317', '9155', '6383', '7793', 'n', '5581', 'v', '3485', 'n', 'r']

Ex Output:
a, c, i, j, n, r, t, v, x


Ex Input:
['j', 'f', '9567', 'f', '7383', 'k', '599', '1091', '1501', 'y', 'o', 'c']

Ex Output:
c, f, j, k, o, y


Ex Input:
['n', 'y', 'y', '4785', 'v', '4007', 'g', 'r', '2529', 'f', '483', 's', 'h', 'r', 'y', 'k', '6393', 'o', '2679', '8595', 'k', 's', '2579', '5871', '2055', '4929', 'b', 's', '4425', '9191', 'x', '8633', 'd', 'a', '5527', 'w', '8481', 'u', 'h', 'h', 'u', '8875', 'i', 'v', '391']

Ex Output:

a, b, d, f, g, h, i, k, n, o, r, s, u, v, w, x, y