using System;

public class Program

{

    public static void Main()

    {

        // http://msdn.microsoft.com/en-us/library/9b9dty7d.aspx

        int[][] matrix = new int[][]{

            new int[]{1,2,3},

            new int[]{4,5,6},

            new int[]{7,8,9}

        };

        DisplayMatrix(matrix);

        DisplayDiagonals(matrix);

        int[][] reveredMatrix = ReverseMatrix(matrix);

    }

    private static void DisplayMatrix(int[][] matrix)

    {

        // Should display matrix as it is declaed in the code

        // 1,2,3

        // 4,5,6

        // 7,8,9

        for (int i=0; i<matrix.Length; i++)

        {

        Console.Write(matrix[i][i]);

        }

    }

    private static void DisplayDiagonals(int[][] matrix)

    {

        // 1   3

        //   5

        // 7   9

    }

    private static int[][] ReverseMatrix(int[][] matrix)

    {

        // should return the following

        // 9,8,7

        // 6,5,4

        // 3,2,1

        return matrix;

    }

}