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.
Love it how the notes explicitly state "nothing but a-z" but the test cases contain uppercase letters and digits too.
Since I expected that to be true I gave a solution that wouldn't have worked with specific inputs.