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 Input:
['k', 'c', 'i']

Ex Output:
c, i, k


Ex Input:
['q', '6421', 'w', 'x', '669', 'h', '3853', '6609', 'p', '947', 'g', 'c', 'x', '2617', 'v', 'e', '4795', '5755', 'a', '2379', 'y', '5939', 'l', 'h', 'g', '3779', 'c', 'm', '3157', '4027', 'g', '2917', '9461', '7271', 't', 'i', '9807', '147']

Ex Output:
a, c, e, g, h, i, l, m, p, q, t, v, w, x, y


Ex Input:
['h', '6393', '6973', '1801', '8509', 'k', '9415', '6959', '8247', 'y', '5483', 'o', '1725', 'x', '9513', '9153', '8651', 'i', '9331', '745', 'v', 'j', '6655', 's', 'v', 'q', 's', 'h', 'q', '211', '6869', '5713', '47', '9675', '5325', 'f', '9179', 'r', 'x', 'r', '6895', 'n', '5673', 'g']

Ex Output:

f, g, h, i, j, k, n, o, q, r, s, v, x, y