Loading collection data...
Collections are a way for you to organize kata so that you can create your own training routines. Every collection you create is public and automatically sharable with other warriors. After you have added a few kata to a collection you and others can train on the kata contained within the collection.
Get started now by creating a new collection.
You're printing the result instead of returning it. Or doing recursion wrong.
Your recursion is wrong.
... what kind of error?
check your python version and make sure you're not doing somehow changing the code while copy pasting