Divide the grid into nine regions, each consisting of nine orthogonally connected cells. Regions do not overlap. Place the digits 1–9 once each in every row, column, and region. Suns: The digit in a sun counts how many of the up to nine cells in the 3×3 square centered on that sun belong to the same region as the sun (including the sun cell itself). Example: If R4C1 = 3, then exactly three of the cells R3C1, R3C2, R4C1, R4C2, R5C1, and R5C2 belong to the same region as R4C1.