Write a challenge

The best challenges come from real problems people actually hit. Draft one here — your own solution is checked against your test cases as you type, so you will know it works before anyone else sees it.

TitleSlug — /c/…

Brief — one or two sentences stating the task

ModeTierYour name — credited on the challengeYour link — optionalTags, comma separated

Test cases

+ must match
- must not match

Visible — shown to the player (0)Hidden — checked on submit (0)

Write a space at the start or end of a value as \s, since lines are trimmed. Also available: \n, \t, \\.

Your solution — this becomes the par

Not ready yet

· Give it a title.
· The brief needs to actually state the task.
· At least three visible test cases.
· At least two hidden test cases.
· Write your own solution — it is the par.
· Match challenges need at least one reject case, or anything passes.