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:
['8235', 't', '1695', '9899', '3633', 't', '1823', 'r', 'x']

Ex Output:
r, t, x


Ex Input:
['n', 'y', '7087', '9539', 'x', 'i', 'w', '7237', '8613', 'k', '5999', '4179', 'o', 'm', '7485', '1955', 'w', '1451', 'h']

Ex Output:
h, i, k, m, n, o, w, x, y


Ex Input:
['7983', 'j', '2821', 't', 'g', '4961', 's', '3139', '4347', '513', '8755', '6161', 'v', 'm', 'p', 's', 'g', 'l', '5903', 't', 'w']

Ex Output:

g, j, l, m, p, s, t, v, w