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:
['m', '7517', '9361', '9567', '8785', 'k', '5699', '3585', 'v', '1913', '1651', 'g', 'p', '2731', 'q', 'h', '467', 'r', '1091', '9801', 'a', '6645']

Ex Output:
a, g, h, k, m, p, q, r, v


Ex Input:
['h', 'b', '9601', 'h', 'h', 'h', '8099', '8265', 'i', 'd', '8791', 'p', '8059', '4309', '501', '2581', '9837', '157', '4785', '5925', 'q', '8491', '4779', 'r', 'l', 'k', '3679', 'v', 'g', 'g', '9731', '1909', '9783', 'f', '4293', '5009', 'o', '3057', '3157', 'c', '5587', 'b', 'f', 'd', 'k']

Ex Output:
b, c, d, f, g, h, i, k, l, o, p, q, r, v


Ex Input:
['e', 'x', '5449', 'q', '4479', '4371', 'y', '3895', 'k', 'w', '2983', 'i', '5217', '7403', 's', '2367', 'j', 'i', 't', 'l', '7023', '4751']

Ex Output:

e, i, j, k, l, q, s, t, w, x, y