Part 1. Definition
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.
Part 2. Example
['8129', 'a', '4245', 'y', 'm', 'a']
Answer: a, m, y
Explanation: Here, the unique alphabets in the list are 'a', 'y', and 'm', hence their sorted order is 'a, m, y'.
Part 3. Exercise
['3055', 'v', 'm', 'a', '905', '6307', 'f', 'k', 'k', '1799', '561', 'w', 'n', 'g', 'y', '6169', '325', 'm', 'a', 'm', '9555', '6879', 'x', '2191', 'v', '7959', '1167', '7973', '7843', 'a', 'z', 'g', 'i', 't', '2457', '8019', 'w', 'q', '6363', 's', '7909']
Answer:
a, f, g, i, k, m, n, q, s, t, v, w, x, y, z