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', '1625']

Ex Output:
d


Ex Input:
['p', '3981', 'e', '5949', 'p', '4075', '1919', 'w', 'r', '8059', '4303', 'f', '5201', '2255', '2737', '7395', '8809', 'j', 'z', 'n', '4797']

Ex Output:
e, f, j, n, p, r, w, z


Ex Input:
['g', 'o', '9971', '1899', '4385', 'x', 'a', 'e', 'u', 'w', 't', 'h', '5465', '3401', '5167', 'l', 'g', '4775', '331', 'a', 'p', 'x']

Ex Output:

a, e, g, h, l, o, p, t, u, w, x