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: ['i', 's']

Output: i, s


Input: Consider Input: ['b', 'a', '7411', '4471', 'z', 'l', '2051', 'q', '6749', '8647', 's', 'y', 'h', '9319', 'e', '5419', 'y', 'q']

Output: a, b, e, h, l, q, s, y, z


Input: Consider Input: ['a', 'k', '5563', 'r', '3239', 'r', '2973', 'o', 'y', 'd', 'z', 'i', 'p', 'k']


Output: a, d, i, k, o, p, r, y, z