link?

No it's 825.

See https://codeforces.net/blog/entry/62865

Approximately this means that if the rating of the problem is equal to yours, then on a typical round you would solve the problem with a probability of 0.5.

Someone with rating 800 had a roughly 50% chance to solve it. Someone with rating 1000 had a roughly 75% chance to solve it. Someone with rating 1200 had a roughly 90% chance to solve it. And so on. It's always possible to have a bad day when luck is not on your side.

This was a Div1 + Div2 round. So a lot of higher rated people solved that problem and the time was also $$$3 hours$$$ so a lot of lower rated people solved that too.

That's why this $$$800$$$ rated problem is actually tougher than most of the other $$$800$$$ you'll find.

It was 1400+ for me. After 40 minutes i just wrote anything and submitted and it passed.