Distinct Sums Grid

Create an n \times n grid that fulfills the following requirements: - Each integer 1 \dots n appears n times in the grid. - If we create a set that consists of all sums in rows and columns, there are 2n distinct values. Input The only line has an integer n. Output Print a grid that fulfills the requirements. You can print any valid solution. If there are no solutions, print IMPOSSIBLE. Cons