//Julissa Patiño Paredes

//3B

//P0202

public class Program

{

  public static void Main()

   {

     int suma, n , x;

     System.Console.WriteLine("introduce hasta que numero deseas sumar");

     n= System.Convert.ToInt32(System.Console.ReadLine());

     suma= 0;

     for(x=1; x<=n; x++)

     {

         suma=suma+x;

     }

      System.Console.WriteLine("la suma es:" + suma);

      System.Console.ReadLine();

   }

}