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.

['k', 'c', 'i']
c, i, k

['o', 'v', 'w', '7939', '571', '395', '3707', 'm', 'd', 'u', 'o', 'r', '4211', '9645', '8731', '2441', 'y', '8147', '8809', 'e', 'b', '6835', 'i', '2083', 't', '3481', 'f', 'f', '5559', '3601', 'e', '5637', '5185', 't', '6777', '3419', '8637', 'p', 's', 'o', 'x']
b, d, e, f, i, m, o, p, r, s, t, u, v, w, x, y

['l', 'c', '9309', '5551', 'i', 'p', '7181', '6023', '7995', 'q', 'v', 'n', 'd', 'm', 'y', 'h', 't', 'g', 'i', '1231', '6485', '8519', '8067', '4281', '4663', '7777', 's', '6879', '1063', '4097', 'h', '6563', 'j', 'm', 't', '3671', 't', '4317', 'q', '7597', 'o', 'a']

a, c, d, g, h, i, j, l, m, n, o, p, q, s, t, v, y