using System;

public class Program

{

    public static void Main()

    {

        int toplam = 0;

​

        for(int i=1; i<=997 ;  i++){

            toplam = toplam + ( i*(i+1)-(i+2)*(i+3));

            Console.Write("("+ i.ToString()+"*"+(i+1).ToString()+"-"+(i+2).ToString()+"*"+(i+3).ToString()+")+");

        }

        Console.WriteLine("\n Sonuç: "+toplam.ToString());

    }

}