This puzzle is a 4 × 4 grid of cells, which are arranged in four rows and four columns of four cells each. Cells are divided into "cell pieces" by grey lines. Write a digit from 1–4 in each cell piece. Digits may not repeat in a cell. In each row, column, and box, the total area of the cell pieces containing the digit 1 must equal the area of a single cell. The same is true for the digits 2, 3, and 4. When cell pieces in the same cell have equal size, you may enter their digits in either order.