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.

Q: ['2329', 'i']

A: i
****
Q: ['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']

A: a, c, e, g, h, i, l, m, p, q, t, v, w, x, y
****
Q: ['y', 'x', 'q', 'x', 'i', '5959', 'j', 'q', '3059', '7649', '6901', '3869', 'i', '4353', 'y', 't', 'v', '4441', 'm', '3787', 'n', 'u', '555', 'o', '8679', '1461', '5973', '8099', 'x', '1999', '229', 'k', 'p', 'n', '8145', 'b', '3065', 't']

A:
b, i, j, k, m, n, o, p, q, t, u, v, x, y
****