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: ['1657', 'u', '1849', '425', 'v', '6435', 'j', '2985', '921', '9553', '2621', 'i', '7103', 'd', '8563', 'l', 'b', '6727', '4235', 'n', '8021', 'd', 'z', '437', 'm', '5695', 't', '3421', 'e', 'a', '2941', '791', '1417', '9247', 'h']

A: a, b, d, e, h, i, j, l, m, n, t, u, v, z
****
Q: ['6769', '1057', '1021', 'n', '8231', '9173', '8123', 'a', '6053', 'q', 'y', '883', 'r', '1215', 'x', 'o', '9531']

A: a, n, o, q, r, x, y
****
Q: ['o', '347', 'f', 'p', '7809', '4903', 'm', '2423', '4601', 'c', 't', 'c', 'z', 'k', '2939', '4607', '7069', 'i', '6563', '3987', '213', 'g', 'v', '8941', '9173', 'm', 'x', 'c', 'd', '159', '8145', '7319', '9745', '9675', '9317', 's', '4823']

A:
c, d, f, g, i, k, m, o, p, s, t, v, x, z
****