public class SumIntRecursion
{

  static 
  int sir ( int i )
  {
    if (i <= 0)
    {
      return 0;
    }
    int j;
    j = sir ( i -1 );
    return i + j;
  }

  public static void main ( String [] args )
  {
      System.out.println(sir(10));
  }

}