In Ruby there are no tests written... You have to write your own, which is considerably more difficult than completing the kata, because who knows what the test cases are? The scenario is so poorly specified, the only way to write the tests, was by submitting the answer, printing the inputs to the console, then using that to write the tests. Is it too much to ask to write proper tests?

This is also an important lesson, do not underestimate it.

Also not many languages have a built-in function which realises the task here. You can try it in Pyton or JS,then you will have to Google for something else than built-in.