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
['4159', 'l', 'd', 'f', '9591', 'u', '3009', '6639', 'z', '8373', 'e', '2713', '747', 'i', 'a', '3699', 'u', '1347', 'v', '6493', '4291', 'y', 'e', 'q', 'k', 't', 'd', '6731', '1219', 'n', 'g', 'z', 't', '6439', 'w', 't', '4403', '5665', 'l', '8887', 'p']
Answer:
a, d, e, f, g, i, k, l, n, p, q, t, u, v, w, y, z