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.

['k', '8917', '3773', '6723', 'r', 'z', '3265', 'o', 'f', 'q', '9343', 'f', '1925', 'u', 'b', 'o', '5275', 'b', 'n', 'd', 'j', '4825']
b, d, f, j, k, n, o, q, r, u, z

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

['1799', '6409', '9257', '5923', 'm', 'j', '2565', '715']

j, m