Reorder numbers 1 through 9 in a white inner box in such way, that the sum of all numbers in any vertical, horizontal or diagonal row equals 15.

To reorder, select a number by clicking it, then select another number to swap it with the originally selected. The row sum dynamically changed as you reorder numbers.

Applying a logic and a base math this puzzle may be solved in 5 minutes. Randomly reordering might take hours or days to solve.