# Oracle Writer Instructions

You are given rows from `data/oracle_seed.jsonl`.

For each row:

1. Read `messages` as the exact chat input. `prompt` is only a flattened fallback for non-chat tooling.
2. Produce an optimized C++20 program that preserves exactly the same stdin/stdout behavior as `source_code`.
3. Return the original input `messages` unchanged, then append exactly one assistant message with:
   - one `<reasoning>...</reasoning>` block;
   - one fenced `cpp` code block;
   - no extra text before, between, or after those two parts.
4. Compile the generated program with the row's `compile.command`.
5. Run all visible tests from `visible_tests`.
6. Fill the `verification` object truthfully.

Do not return partial-credit rows for training. If a solution does not compile or does not pass tests, mark it as failed and do not call it oracle data.

The expected output JSONL shape is shown in `data/oracle_return_example.jsonl`.