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.

['n', 'q', '6461', 's', '8565', '2237', '2071', '8143', '2977', '5511', 'j', 'o', '5793', 'j', 'm', 'n', '8031', 'j', '535', '5001', 's', 'y', '1737']
j, m, n, o, q, s, y

['y', 'i', '257', '3695', 's', '6717', '4817', '4117']
i, s, y

['o', 'k', 'm', 'i', 'l', '395', '3297', '6787', 'p', '2603', '6721', 'g', 'c', 'f']

c, f, g, i, k, l, m, o, p