Hi every one!

It is 7 days more to the next Codeforces round but only 9 hours to my first Cook-Off at Codechef.com . Let's participate and have fun!

I want to give my special thank to Anton_Lunyov. His is an experienced problem tester and made a huge improvement for my test data. I also want to thank Suraj for the system and letting me do this interesting job.