static void Main(string[] args)
        {
            AI ai = new AI();

            do
            {
                Console.Clear();// whenever loop will be again start then screen will be clear
                Console.WriteLine("Player1:X and AI:O");
                Console.WriteLine("\n");

                Board();             // calling the board Function

                if (player % 2 == 0) //checking the chance of the player
                {
                    Console.WriteLine('\n' + "AI Chance");
                    choice = ai.getMove(arr);
                }

                else
                {
                    Console.WriteLine('\n' + "Player 1 Chance");
                    choice = int.Parse(Console.ReadLine());//Taking users choice
                }



                //checking that position where user want to run is marked(with X or O) or not
                if (isValid(arr, choice))
                {
                    if (player % 2 == 0)
                    { //if chance is of player 2 then mark O else mark X
                        arr[choice] = 'O';
                        player++;
                    }

                    else
                    {
                        arr[choice] = 'X';
                        player++;
                    }
                }

                else
                { //If there is any possition where user want to run and that is already marked then show message and load board again
                    Console.WriteLine("Sorry the row {0} is already marked with {1}", choice, arr[choice]);
                    Console.WriteLine("\n");
                    Console.WriteLine("Please wait 2 second board is loading again.....");

                    Thread.Sleep(2000);
                }

                flag = CheckWin();             // calling of check win
            } while (flag != 1 && flag != -1); // This loof will be run until all cell of the grid is not marked with X and O or some player is not win

            Console.Clear();                   // clearing the console

            Board();                           // getting filled board again

            if (flag == 1)                     // if flag value is 1 then some one has win or means who played marked last time which has win
            {
                Console.WriteLine("Player {0} has won", (player % 2) + 1);
            }

            else // if flag value is -1 the match will be draw and no one is winner
            {
                Console.WriteLine("Draw");
            }

            Console.ReadLine();
        }