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.

['57', 'j', 'n', '877', 'u', 'w', 'j', 'f', '8977', 'h', '469', '9417']
f, h, j, n, u, w

['3821', '385', 'y', '8457', '6623', 'g', '5923', 'a', '7193', 'v', 'm', '8915', 'v', '5873', 'p', 't', 'w', 'y', '3617', 'h', 'w', 'j', '8047', 'u', '2271', 'v', 'a', '2181', 's', '1051', 'b', 'a', '9967', '987', 'z', '2255', '6349', '1249', '1397', 'q']
a, b, g, h, j, m, p, q, s, t, u, v, w, y, z

['5717', 'n', 'r', '175', '2103', '5315', '7669', '1411', 'l', '6045', '5801']

l, n, r