h(x) = 2f25b8b14f3048396c833cb353977a2313f9057800e9b5e32a5f279d2aa6a316
author: unknown
h(x) looks like a cryptographic hash, and refreshing the page shows it changes every 5s. We find that the SHA256 hash of the unix time (floored by 5 seconds) gives us the same hash. Thus the answer is the current unix time (and values within ± a minute are accepted).