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', 'r', 'f', '4369', 'z', 'z', 'l', '143', 'r', '707', '9167', 'g', '1749', 'i']
f, g, i, k, l, r, z

['f', '9027', 'z', '9601', 'w', '7747', '1135', 'j', '1871', 'd', 'u', 'f', 'd', 'x', 'k', '2009', 't', '4625', 'm', '1619', 'm', 'm', '3107', 'x', '3957', '2495', 'j', '201', 'a', '4635', 'r', '7407', 'b', 'r', 'z']
a, b, d, f, j, k, m, r, t, u, w, x, z

['a', '7411', '97', 'x', 'n', '2299', 'u', 'x', '13', 'g', 'z', '7669', 'b', 'x', '3699', '5313', 'i', 'h', 'm', '5761', 'j', 'c', '2535']

a, b, c, g, h, i, j, m, n, u, x, z