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.

['i', '4447', 'g', 'o', 'j', 'p', 'l', 'q', 'o', '8777', 'r', 'v', '961', '6083']
g, i, j, l, o, p, q, r, v

['w', '491', 'x', 'u', 'z', 'q', '5411', '7629', '8261', '8629', '1441', '5139', 's', 'm', '6463', 'u', 'z']
m, q, s, u, w, x, z

['6449', 'j', '7515', '5317', '155', 'k', '7747', '2635', 'k', 'y', 'h', 'l', 'q', '2309', '5595', '2851', 'l', 'f', '5177', '8709', 'c', '403', 'h', 'b']

b, c, f, h, j, k, l, q, y