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 could make this a little more difficult by also accepting negative amounts (formatted correctly ;) and requiring the function to throw an error if the running total drops below zero.. it's fine for beginners though.