PLEASE READ THE FOLLOWING:
There is a minimum criteria you must meet for submitting a good challenge:
1. Challenges should be described in a fun and lighthearted, even if difficult. Give your challenge a theme, such as "you're on a mission to mars" or "you're a robot trying to buy cupcakes".
2. Your description should be at least three short paragraphs: You should have a general background, then a detailed explanation of the task, and a final example walk-through.
3. Challenges must be easy to describe and without the need of specialized knowledge outside of programming. If a developer cannot research and understand any knowledge-dependencies (outside of general programming) in a few minutes, then your challenge is too specialized of a topic.
4. Make the title interesting; it does not have to explicitly say what you are doing in the challenge.
5. Set the difficulty to an appropriate level. Easy challenges have trivial brute-force solutions. Intermediate challenges may have some sorting and searching involved, and though can be solved through brute-force, are too complex to solve without algorithms. Hard challenges are generally comparable to NP / NP-complete problems, like the Traveling Salesman Problem.