This will be a mirror of the 2025 International Olympiad in Informatics (IOI 2025) Day 1.

This contest is not rated.

Note that problem 2 was originally split into two separate problems for the respective subtasks; however, we have merged both back into one problem (and so old contest participations may be inaccurate).

• Problems 1, 2, and 3 will be C++ only.
• Contest duration: 5 hours.
• Number of problems: 3.
• Each problem is worth 100 points with subtasks that offer partial credit.
• Partial output: None.
• You may make up to 50 submissions for each task.
• Scoreboard will be visible.