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.

['6599', 'f', 'c', '661', 'q', 'e', '1951', 'f', 'f', 'a', 'd', '9521', '853', 'n', 'w', '6451', '5549', 'k', 't', 'l', 'z', 'm', 'k', '567']
a, c, d, e, f, k, l, m, n, q, t, w, z

['1063', 'f', 'm', 'i', 'x', 'i', 'd']
d, f, i, m, x

['8757', '501', '6561', '2357', 'q', '6275', '3415', '6865', '4271', 'b', 'b', 'u', 'o', 't', 'a', 'l', '6289', 'x']

a, b, l, o, q, t, u, x