Hello, Codeforces.

I'm Coffee_zzz. To celebrate my 15th birthday, I hold a contest on Luogu.

• Contest URL: https://www.luogu.com.cn/contest/205839
• Contest Time: https://www.timeanddate.com/worldclock/fixedtime.html?iso=20241019T1330&p1=237
• System: IOI
• Duration: 210 minutes
• Difficulty: Codeforces Div.3-Div.2
• Coordinator: Coffee_zzz
• Testers: xuwt, dXqwq, rui_er, frostaur_, acwing_gza, shiqingbaiya666, monster_hunter, McIron233, andychen2012, MSTqwq, wyrqwq, Nahidameow, shinzanmono, _saixingzhe_, E.Space, VinstaG173
• Score Distribution: 100-100-100-100

I'm looking forward to your participation! English statement will be provided officially.

• A tutorial on using Luogu