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]: ['4637', 'f', '2639', '8623', 'w', 'e', 'k', '5503', 'x', '6633', '7553', '1455', 'u', '1773', 'r', 'u', '1489', 'u', '1303', '9683', 'z', '565', '7041', 'x', 'z', '9431', 'k', 'v', 'j', 'z', '5469', '5665', '4089', '4951', '8263', '5675', '4095', '7745', 'z', '2437', 'd', 'e', 'w']
[EX A]: d, e, f, j, k, r, u, v, w, x, z

[EX Q]: ['6955', '721', '2763', '8121', '9109', '6341', 'p', 't', 'x', '6963', '1137', 'z', 'u', '1949', '7029', 't', '9539', 'a', 'u', '1873']
[EX A]: a, p, t, u, x, z

[EX Q]: ['8619', 'x', '3243', 'e', 'n', '2241', '8875', 'i', 'e', '219', '3337', '7685', '7541', 'k', 'y', 'o', '4585', '8643', 'w', 'e', '1179', 's', '5479', '2799']
[EX A]:
e, i, k, n, o, s, w, x, y