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:
['y', '8115', 'f', '5333', 'f', '3437', 'b', 'e', '5719', 'm', 'w', '95', '4863', 'k', '4895', 'a', '8179', 'm', '7919', '1731', '229', 'r', '1847', '7559', '6669']

Ex Output:
a, b, e, f, k, m, r, w, y


Ex Input:
['t', 'x', '1699', '8727']

Ex Output:
t, x


Ex Input:
['4545', 'g', '9249', 'y', 's', 'o', 'e', 'y', 'm', 'u', 'i', 'w', '145', '3917', '2963', '2137', 'u']

Ex Output:

e, g, i, m, o, s, u, w, y