Calcudoku is a Sudoku-like puzzle — given an \(n \times n\) grid, fill it withn the digits \(1, ..., n\) such that no row or column contains a repeated digit, and such that each cage’s condition is satisfied. For example, a cage with \(5+\) in a corner must have its contents sum to 5. A cage with \(2-\) is a little more complicated — it means that choosing some cell in the cage and subtracting the others results in 2. So a 3-cell cage containing 5, 2, and 1 would work. Division cages are written with a colon and works similarly to subtraction. Finally, cages with no operation at all are always \(1 \times 1\), and simply contain the number in the corner.