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: ['p', '5229', '7521', 'y', 'n', 'u', 'c', '4047', '781', 'a', '4707', '7149', 'j', 'm', 't', '515', '7691', 'h', '4879', 'j', '6593', 'n', 'p', '2949', '1343', 'y', '2629', 'p', 'b', 'b', '2861', 'a']

Output: a, b, c, h, j, m, n, p, t, u, y


Input: Consider Input: ['2527', '9123', '8717']

Output: -1


Input: Consider Input: ['k', 'k', 'r', 'j', '1325', '2507', '5575', 'b', '1589', 'j', '1421', '8977', 'l']


Output: b, j, k, l, r