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:
['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:
['v', '3765', '4065', 'a', '4201', 'f', 'x', '9275', 'q', '9303']

Ex Output:
a, f, q, v, x


Ex Input:
['x', 'i', '3989', 'k', '3267', 'z', 'r', '5861']

Ex Output:

i, k, r, x, z