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', 'v', '1099', 'y', '1313', 's', '181', 'u', 'e', 'u', '8435', '4125', '8661', 'c', '4605', 'f', 'x']

Output: c, e, f, p, s, u, v, x, y


Input: Consider Input: ['1121', 'j', '1433', 'g', 'l', '1479', '1699', 'j', 'a', '8507', 'd', 'a', '5229', 'k', 'x', '4549', 'e', 'p', '1367', 'u', 'd', '785', '215', 'e', 'f', 'a', '101', '7575', '7965', 'p', 'i', '5637', '1005', 'i', 'y', '181', 'r']

Output: a, d, e, f, g, i, j, k, l, p, r, u, x, y


Input: Consider Input: ['y', 'g', '107', '4899', '6357', '9777', 'k', '1865', '7029', 'q', 'x', '7051', 's', '6125', '4285', '2731', 'z', 'a', '737', '6137']


Output: a, g, k, q, s, x, y, z