Halting Condition

 public class Main {

  public static void main(String[] args) {

    int result = sum(5, 10);

    System.out.println(result);

  }

  public static int sum(int start, int end) {

    if (end > start) {

      return end + sum(start, end - 1);

    } else {

      return end;

    }

  }

}