Массив с# N2

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            float var = 0;
            Console.Write("Write n:");
            int n = int.Parse(Console.ReadLine());
            Console.Write("Write m:");
            int m = int.Parse(Console.ReadLine());
            float[,] massiv = new float[n, m];
            Console.WriteLine("Write massiv [{0}][{1}]:", n, m);
            for(int i = 0; i < n; i++)
            {
                for(int j = 0; j < m; j++)
                {
                    Console.Write("massiv[{0}][{1}]:", i, j);
                    massiv[i, j] = int.Parse(Console.ReadLine());
                }
                Console.WriteLine(" ");
            }



            for (int i = 0; i < n; i++)
            {
                for (int j = 0; j < m; j++)
                {
                    var += massiv[i, j];
                }
                Console.Write("randka:{0} | Sum:{1} | ", i, var);
                var /= m;
                Console.WriteLine("Arifm:{0}", Math.Round(var, 2));
                for (int j = 0; j < m; j++)
                {
                    massiv[i, j] -= var;
                }
                var = 0;
            }

            Console.WriteLine("massiv[{0},{1}]:", n, m);

            for (int i = 0; i < n; i++)
            {
                for (int j = 0; j < m; j++)
                {
                    Console.Write("[{0}][{1}]:{2} ", i, j, Math.Round(massiv[i, j]), 2);
                }
                Console.WriteLine();
            }

            Console.ReadKey();
        }
    }
}