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.

['6027', 'v', 'b', 'l', '7853', 'r', 'y', '2919', '3831']
b, l, r, v, y

['9925', 'f', '6149', 's', 'd', 's', '75', '8577', '2319', 'b', '3769', '5211', 'q', 'm', '8127', 'f', '3801']
b, d, f, m, q, s

['7095', '8515', 'h', 'd', '6883', '9171', 'o', '9939', '7287', 'p', 's', 'i', 'z', '305', 'g', '4103', 'w']

d, g, h, i, o, p, s, w, z

