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: ['3395', '7471', 'n', '9537', '1255', '1997', '3085', '4863', '9797', '4275', 'k', 'f', '8973', '3939', 'p', 'q', '4977', '6231', '8745']

A: f, k, n, p, q
****
Q: ['x', 'u', 'm', '8089', '9985', 'e', '2927', 'n', '7085', 'q', 'v', 'f', 'p', '5079', '3339', '7871', 'h', '7389', '733', 'e', '3387', 'b', 'x', 'z', '2039', 'u', '59', '5031', '8115', '5447', '3045', 'x', '6591', '9561', '4315']

A: b, e, f, h, m, n, p, q, u, v, x, z
****
Q: ['m', 'b', 'q', '2385', '8707', 'l', 'v', '251', '1343', '5397', '9561', 'a', '1653', 'y', 'x', 'b', 't', '4021', '3895', 'r', 'a']

A:
a, b, l, m, q, r, t, v, x, y
****