log* is <a href="https://en.wikipedia.org/wiki/Iterated_logarithm" rel="nofollow">https://en.wikipedia.org/wiki/Iterated_logarithm</a><p>aka inverse of tetration
I solved this in the worst way. Took a (correct) guess at what was meant by prefix, and then brute-forced a dozen of them. Did you know that zetta.ai is also an AI company?
Haven't read past the problem statement to avoid spoilers.<p>How difficult can it be to brute force this. (Try all possible domain names within a reasonable length)<p>Take help from AI while you are at it.