This is a Suduro puzzle. Fill in the gray squares with numbers 1-9 so that the gray squares in each column and row add up to the sums clues in the top-edge and left-edge black squares. Similarly, the upper-left 3-by-3 grid of numbers shows the gray-squares sums for the corresponding 3-by-3 sub-grids. Fill in the white squares to complete a normal Sudoku puzzle, so every row, column, and 3-by-3 sub-grid has each number 1-9 exactly once.
