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: ['c', '8785', 'u', 'i', 'i', '6513', '6093', 'w', 'i', 'x', '9377', 'p', '1545', '7997', 'a', 'c', '125', 'u', '9149', '9103', 'u', 'o', 'h', '2275', '8503', '3251', 'c', '9925', 'w', '6873', 'c', 'h', 'e', '2369', 'c', 'z', '1337', '9541', '675', 's']

Answer: a, c, e, h, i, o, p, s, u, w, x, z


Question: ['z', '2519', '4799', '4715', '7165', 'r', 'r', 'l', 'n', '6925', '8935', '9795', '5489', 'v', 'u', '6527', '2241', 'u', 'c', 'w', '9755', 'w', '9823', 'g']

Answer: c, g, l, n, r, u, v, w, z


Question: ['1347', '1535', '4437', '1047', 'c', '9017', '4129', '165', 'd', 'x', 'o', '2745', '7705', 'g', '2597', '805', 's', 'v', 'o', 's', '9991', 'd', 'a', '8323', 's', '143', 'f', 't', 'r', 'q', '9633', '7515', '7939', '3715', 'x', '617', 'p', '3269', '9143', 'c', 'p', 'g', '4555']

Answer:
a, c, d, f, g, o, p, q, r, s, t, v, x