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: ['477', '3931', 'g', '5967', 'm', '9845', '1607', 'a', '1749', 'k', 'j', '7945', '9125', 'v', 'n', 's', '5185', '1117', '17', 'x', '4149']

Output: a, g, j, k, m, n, s, v, x


Input: Consider Input: ['333', 'b', '261', 'k', 'p', '7861']

Output: b, k, p


Input: Consider Input: ['3011', '6843', '3851']


Output: -1