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.
--------
Question: ['8495', 'p', 'j', 'm', 'n', '9115', '1183', 'r', 'r', '8735', 'a', 'i', 'k', 'p', '8927', 'r', '9283', '9563', 'g', '2503', 'h', '1091', '5257', 'a', '3061', '2835', 'l', 'w', 'j', '7617', '8793', '7463', 'h', '8467', '7337', 'b', '4655', 'd']

Answer: a, b, d, g, h, i, j, k, l, m, n, p, r, w


Question: ['j', 'a', 'z', 'h', '4129', '4159', 'm', 'o', 'o', '1193', '2905', '3083', 'q', 't', 'm', 'o', '673', '7547', 'n', 'c', 'r', 't', '2897', '4959', 'z', '2377', 'y', '7977', 'u', 'b', 's', 'w', 'e', 'd', '8051']

Answer: a, b, c, d, e, h, j, m, n, o, q, r, s, t, u, w, y, z


Question: ['2167', '7999', 'r', '6163', 's', 'z', '9729', '7863', '9437', 'g', 'k', '7229', '5685', '6983', '4621', '2545', '1823', 'e', 'q', '691', '2509', 'b', '5249', 's', 'j', 'k', '2039', 'x', 'x', '5401', 's']

Answer:
b, e, g, j, k, q, r, s, x, z