You are solving a competitive programming problem.

Problem directory: /app
- Read statement.txt for the full problem description
- Time limit: 5.0s, Memory limit: 1024m
- Total test cases: 16
- Scoring is partial: 0-100% based on fraction of test cases passed

## Problem type: INTERACTIVE

This is an interactive problem. Your solution communicates with a hidden judge
via stdin/stdout. You do NOT read from files.

Read AGENT.md in this directory for compilation, testing, and workflow guidance.
You can call `bash /app/submit.sh` at any time during this task to get a graded
score and feedback on `/app/solution.cpp` from the same judge that scores the
final result. Submit early and iterate.
Begin by reading the full problem statement in statement.txt.