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.

['g', 'u', 'q', '1375', '9491', 't', 'w', 'c', 'v', 'y', '3169', '1607']
c, g, q, t, u, v, w, y

['887', 'p', '3819', '2727', '1407', 'b', 'n', '737', 'd', 'w', 'q', '6877']
b, d, n, p, q, w

['2325', '2479', '449', '1585', 'v', '4513', 'k', '1309', '7471', '9309']

k, v