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: ['m', '3809', 'l', 'k', '1929', '7963', 'n', 'u', '2125', 'g', 'o', '8325', 'o', 'h', 'y', '3025', 'e', 'e', 'c', 'x', '8445', '4979', 'z', 'f', '4201', '4765', 'g']

Answer: c, e, f, g, h, k, l, m, n, o, u, x, y, z


Question: ['5737', 'b', 'e', 't', '7419', 'n', 'y', '5225', '6485', 'b', '1343']

Answer: b, e, n, t, y


Question: ['5395', 'u', '2643', 'u', '3407', 'a', '7191', '7535', 'x', 's', 'v', '3315', '8461', 't', 'v', 'f', '4381', 'c', 'h']

Answer:
a, c, f, h, s, t, u, v, x