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.

[EX Q]: ['1945', 't', '4477', '4439', '6569', '2021', 'y', 't', '2725', '8947', '6921', '1373', '8107', 'g', 'c', 'w', 'x', 'b', '9117', 'k', '6567', '5073', '2307', 'e', 'b', '7405', 'e', 'x', '1419', 'd', 'o', 'n', 'a', '2647', 'z', '1459', 'n', '6137', 'u', 'b', 'q', '4459']
[EX A]: a, b, c, d, e, g, k, n, o, q, t, u, w, x, y, z

[EX Q]: ['k', 'n']
[EX A]: k, n

[EX Q]: ['4563', 's', '1657', '559', '4027', 'a', 'p', 'r', '1973', '335', 'w', '1579', '299', '6025', '8405', 'c', '7815', '2187', 'r']
[EX A]:
a, c, p, r, s, w