using System;

​

public class Program

{

     public static int [,] nhapmatran (string ghichu)

        {

            int[,] arr;

            Console.WriteLine("Nhap so dong: ");

            int n = int.Parse(Console.ReadLine());

            Console.WriteLine("Nhap so cot: ");

            int m = int.Parse(Console.ReadLine());

            arr = new int[n,m];

            for(int i = 0; i < n; i++)

            {

                for(int j =0; j <m; j++)

                {

                    Console.WriteLine("Nhap phan tu A[{i} {j}]");

                    arr[i,j] = int.Parse(Console.ReadLine());

​

                }

            }

            return arr;

        }

        public static void xuatmatran (int [,] arr)

        {

            for (int i = 0; i < arr.GetLength(0); i++)

            {

                for (int j = 0; j < arr.GetLength(1); j++)

                {

                    Console.Write("{arr[i, j]} ");

                }

                Console.WriteLine();

            }

        }

        public static int sum(int[,] arr)

        {

            int sum = 0;

            for (int i = 0; i < arr.GetLength(0); i++)

            {

                for (int j = 0; j < arr.GetLength(1); j++)

                {

                    sum = sum + arr[i, j];

                }

            }

            return sum;

        }

    public static bool kimtrasonguyento(int n)

        {

            if (n <= 1)

                return false;

​

            for (int i = 2; i <= Math.Sqrt(n); i++)

            {

                if (n % i == 0)

                    return false;

            }

​

            return true;

        }

    public static int demsongto(int[,] arr)

        {

            int dem = 0;

            for (int i = 0; i < arr.GetLength(0); i++)

            {

                for (int j = 0; j < arr.GetLength(1); j++)

                {

                    if (kimtrasonguyento(arr[i, j]))

                    {

                        dem++;

                    }

​

                }

            }

            return dem;

                public static int tinhtongduongtrendong(int [,] arr)

        {

            int dem = 0;

            Console.WriteLine("nhap so dong can tinh: ");

            int k = int.Parse(Console.ReadLine());

            for(int i = k; i < k+1 ; i++)

            {

                for(int j = 0; j< arr.GetLength(1); j++)

                {

                    1if(arr[i,j] > 0)

                    {

                        dem = dem + arr[i,j];

                    }

                }

            }

            return dem;

        }

         public static void Main(string[] args)

        {

            int[,] arr;

            arr = nhapmatran("Nhap ma tran");

            xuatmatran(arr);

            int kq = tinhtongduongtrendong(arr);

            Console.WriteLine("Ket qua la: {kq}");

         }

    }

​