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: ['895', '2049', '8839', '1773', 'v', '467']

Output: v


Input: Consider Input: ['9271', '6393', '6005', 'x', '2301', '3999', 'p', 'z', 'j', '1033', '7555', 'r', 'r', 'y', '8917', '5939', '4031', 'e', '8095', 'g', '6095', 'a', '4133', '6471', '2129', '8021', '1093', 't', '8805', '545', 'k', '3249', 'l', '1561', '9909', 's', '1963', 'o']

Output: a, e, g, j, k, l, o, p, r, s, t, x, y, z


Input: Consider Input: ['6239', 'g', '1641', 'l', 'u', 't', '8613', '6695', '1107', 'n', '2507', 'j', 'n', '4189', 'p', '2707', 'z', 'o', 'h', 'a', 'n', '5645', '5465', 'x', '1063', '4375', '9901', '8331', '5341', '4551']


Output: a, g, h, j, l, n, o, p, t, u, x, z