The River Crossing

Solve a classic constraint puzzle using a step-by-step prompt that forces the AI to verify each step before proceeding.

Skills Tested

Constraint satisfactionStep-by-step reasoningBacktracking

Challenge Prompt

This is the example prompt structure. Write your own variation below.

Solve this puzzle using strict step-by-step reasoning. A farmer must cross a river with a fox, a chicken, and grain. Boat holds farmer + one item. Fox eats chicken if alone together. Chicken eats grain if alone together.

Mandatory steps:
1. List all constraints explicitly.
2. Identify which pairs cannot be left alone.
3. For each move, state: what crosses, what stays, whether any constraint is violated.
4. If a constraint is violated, backtrack and try again — say "BACKTRACK" explicitly.
5. State the final crossing sequence.

Your Prompt

Write your own version. Every word matters — be specific.

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Reward

+100 GeraCoins

Earn GeraCoins for completing this challenge. Redeem across all Gera products.

Hints (3)

1"BACKTRACK" as an explicit keyword creates a recoverable reasoning trace.
2Step 3's constraint check per move prevents the AI from leaping to the solution.
3This puzzle has two valid solutions — both are acceptable.