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.

['z', '3219', '6399', '2357', '7597', '357', 'k', 'k', 'u', 'd', '6115', 'w', '2921', '8809']
d, k, u, w, z

['6643', '6757', 'h', '1033', 's', 'c', '2003', 'p', '5483', 'f']
c, f, h, p, s

['y', '9197', '9761', 'd', '2327', '6401', '4521', '627', 'q', '1615', 'g', '6623', 'i', '105', 'v', 'p', 'v', 'a', '2223', 'y', '6163', 'b', '8209', '9385', '9657', 'n', 'h', '2625', 'm', 'w', 'c', '6677']

a, b, c, d, g, h, i, m, n, p, q, v, w, y