not getting it

Question

https://www.sololearn.com/coach/66?ref=app

Answer 1

Encode input as:
Convert input to all lower case letters, and then..
a to be replaced by z
b to be replaced by y
c to be replaced by x
...
..
y to be replaced by b
z to be replaced by a

Ex:
Input " abcd"
Output required is "zyxw"..

Answer 2

Show what you tried....
Adding link question will not work..
Please add it in description.. &
Add relavent tags..
I think, code coach, problem title will best fits instead of help, solve this....
Edit :
Thanks for edit

Answer 3

That whole question, i'm unable to understand what it wants