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
['5671', '8009', '6913', '8485', 'q', 'c', '1339', 'w', 'n', '3463', 'p', 'z', '7793', '9543', 'p', '2803', 'y', '7949', '4201', '1077', '8355', '3137', 'r', 'v', 'k', 'g', 'g', '9023', '3191', '8839', '3157', 'g', '7423', '6003']
Answer:
c, g, k, n, p, q, r, v, w, y, z