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: ['8495', 'p', 'j', 'm', 'n', '9115', '1183', 'r', 'r', '8735', 'a', 'i', 'k', 'p', '8927', 'r', '9283', '9563', 'g', '2503', 'h', '1091', '5257', 'a', '3061', '2835', 'l', 'w', 'j', '7617', '8793', '7463', 'h', '8467', '7337', 'b', '4655', 'd']

A: a, b, d, g, h, i, j, k, l, m, n, p, r, w
****
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: ['r', '6435', '7999', '6213', '8811', '1613', '7555', '4623', '2555', '3085', 'n', '427', 'r', '1423', 'd', 'q', 'f', '4661', '3647', 'u']

A:
d, f, n, q, r, u
****