Place a digit from 1 to 9 into each of the empty squares so that each digit appears exactly once in each of the rows, columns and the nine outlined 3x3 regions.

Each number outside the grid is the sum of the first X numbers placed in the corresponding direction, where X is equal to the first number placed in that direction.

If you cannot print the title, please select the print background image in the print settings option.In order to get a better printing result, it is suggested to set up the size of paper and scale.