Hello, Codeforces, I’m from the year 2037.

The time machine was actually invented back in 1967, but it was kept secret until 2027. We couldn't reveal this technology for a long time because of its potential consequences—historical events could have been altered, and the results could have been catastrophic. However, by 2030, we developed strict rules and protocols for using the time machine to avoid disrupting the space-time continuum.

The technology has proven useful for studying the past and solving global issues, such as preventing environmental disasters and wars. However, travel into the future remains restricted for public use—we still don't fully understand the risks.

Feel free to ask questions! Are you curious about history or want to know how the world has changed over time?

At yesterday's competition Div. 3, my solution to problem D crashed on the system test and gave the verdict: Memory limit exceeded on test 9, but when I sent the same code after the system test it passed!

Code that crashed on system testing — 247076528.

Code that passed after system testing — 247189952.

They are identical! It's very strange why this happened, because the limits are small and I was sure that my task would pass system testing.