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
['1753', '1933', 'u', 'a', 'r', '4625', 's', 'p', 'r', 'h', 'c', '2765', 's', '373', '4421', 'k', 'g', '7827', '7773', 'u', '3949', 'u', 't', 'c', 'y', '29', '1307']
Answer:
a, c, g, h, k, p, r, s, t, u, y