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.

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

Output: f, k, n, p, q

Input: Consider Input: ['g', '6867', '7965', '3313', 'k', '1827', '7337', 'u', '1209', '5145', 'w', 'h', '9059', 'u', 'b', '3189', '2837', 'k', 'y', 'e', 'b', '4479', '541', '7103', 'h', 'm', '2177', '6377', '3993', '7167', 'q', '2145', '5007', '9135', '5331', 'e']

Output: b, e, g, h, k, m, q, u, w, y

Input: Consider Input: ['3317', 'r', '3473', '4063', '3477', '1661', '2411', '9905', '1735', 'k', 'i', '9467', 'x', '5421', 'g', 'q', 'l', '3573', 'z', 'l', '1769', 'v', '9185', 't', '1239']
Output: g, i, k, l, q, r, t, v, x, z