Q: 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.
['1381', '5489', '6145', 'k', '6013', '8113', 'o', 'm', 'g', 'r', 'g', '9573', 'o', 'q', '8139', '2093', 'k', '6351', 'u', '6819', '929', 't', 'f', 'q', '2423', 'q', '9137', 'o', '2549', 'b', 'd', '3313', 'm', 'w', '7489', '8149', 'k', '2583', 'c', 't']
A:
b, c, d, f, g, k, m, o, q, r, t, u, w