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.

['z', '8763', '6399', '45', '6731', 'v', '441', '4763', 'u', '8741', 'r', '9143', 'd', 'p', '2241', 'y', '6523', 'y', 'w', '6771', 't', 'r', '9239', '295', 'z', '461', 'b', '9217', '2597', '1249', 'r', 'i']
b, d, i, p, r, t, u, v, w, y, z

['2293', 'p', '9787', '7241', '8689', 'u', '3141', 'h', 'c', 'b', 'f', 's', '319', 'c', 'p', '6909', 'p', 'f', '1717', 'd', '2285', 's']
b, c, d, f, h, p, s, u

['9527', '2091', 'n', 'p', '8125', '4537', '8713', '7221', 'f', '2981', 'k', 'u', 'o', 'c', 'v', '7585', '6921', '2291', 'a', '1473', '3013', 't', '5385', '1167']
a, c, f, k, n, o, p, t, u, v