Send a reply saying that you’ve completed the challenge. Say you’ve hidden the repo somewhere in the interwebs and in order to find it the recruiter will need

Send a reply saying that you’ve completed the challenge. Say you’ve hidden the repo somewhere in the interwebs and in order to find it the recruiter will need to solve three riddles, each one more difficult than the last. Then include just one final line of random characters and an encouraging “good luck!”