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.
V inefficient for large lists though
Closing as less informative than the issue by @nerdgasm above.
Not sure how this is working. Mind explaining?
Should be tested better for invalid card numbers as it seems some of them has been already passed.
That was not clear what I have to do with the r constant.