/*
 * C# Program to Find the Sum of the Values on
 * Diagonal of the Matrix
 */
using System;
using System.Collections.Generic;
using System.Text;
class mat
{
    int i, j, m, n;
    int[,] a = new int[20, 20];
    public void get()
    {
        Console.WriteLine("Enter Row Value");
        m = int.Parse(Console.ReadLine());
        Console.WriteLine("Enter Column Value");
        n = int.Parse(Console.ReadLine());
        Console.WriteLine("Enter Elements one by one");
        for (i = 1; i <= m; i++)
            {
                for (j = 1; j <= n; j++)
                    {
                        a[i, j] = int.Parse(Console.ReadLine());
                    }
            }
        Console.WriteLine("Given Matrix");
        for (i = 1; i <= m; i++)
            {
                for (j = 1; j <= n; j++)
                    {
                        Console.Write("\t{0}", a[i, j]);
                    }
                Console.WriteLine();
            }
    }
    public void diag()
    {
        int d;
        d = 0;
        if (m == n)
            {
                for (i = 1; i <= m; i++)
                    {
                        for (j = 1; j <= n; j++)
                            {
                                if (i == j)
                                    {
                                        d = d + a[i, j];
                                    }
                            }
                    }
                Console.WriteLine("Diagonal Sum= {0}", d);
            }
        else
            {
                Console.WriteLine("Can't Perform Diagonal Sum");
            }
    }
    class matsum
    {
        static void Main(string[] args)
        {
            mat ma = new mat();
            ma.get();
            ma.diag();
            Console.Read();
        }
    }
}

/*
Enter Row Value : 2
Enter Column Value : 2
Enter Elements One by One :
2
2
2
2
Given Matrix :
  2   2
  2   2
Diagonal Sum :4