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
['1085', 'c', '9507', 'u', 'g', '5251', 'k', '7689', 'j', 'u', 'u', 'r', '4695', 'f', 'n', 'd', '935', '1889', 'u', '1671', '9531', '309', '4381', 'w', 'd', '613', '6805', 't', '1711', '3599', '8429', '1285', '1685', '2085', 'z', '5375', 'e', 'n']
Answer:
c, d, e, f, g, j, k, n, r, t, u, w, z