Массив с# N1

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)
        {
            int var = 0;
            Console.Write("Write n:");
            int n = int.Parse(Console.ReadLine());
            Console.Write("Write m:");
            int m = int.Parse(Console.ReadLine());
            int[,] massiv = new int[n, m];
            int[] veck = new int[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(" ");
            }

            Console.WriteLine("Write veck [{0}]:", n);
            for (int i = 0; i < m; i++)
            {
                Console.Write("veck[{0}]:", i);
                veck[i] = Convert.ToInt32(Console.ReadLine());
            }

            for (int i = 0; i < n; i++)
            {
                for (int j = 0; j < m; j++)
                {
                    var = var + massiv[i, j] * veck[j];
                }
                massiv[i, 0] = var;
                var = 0;
            }
            Console.WriteLine("============");
            for(int i = 0; i < n; i++)
            {
                Console.Write("massiv[{0}]:{1}  ", i, massiv[i, 0]);
            }
            Console.ReadKey();
        }
    }
}