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
['g', 'd', 'k', '6779', '9869', '9467', '7499', '6397', 't', '4859', 'l', '8895', '6677', '637', '3305', 'z', '5587', 't', '6247', 'l', '9819', '7887', '8069', 't', 'x', 's', '2107', 'h', 's', '8403', '3609', '3339', '471', 'o', 'j', '4367', '3897', '2787', '7747', '8971', '6393', 'z', '8113', '3515', 't']
Answer:
d, g, h, j, k, l, o, s, t, x, z