class Etest{
  private static int check(int n)
    throws Exception
  {
    if (n<0)
      throw new Exception(n + " is negative.");
    return n;
  }
  public static void main(String[] args){
    int s = 0;
    try{
      s += check(-1);
    }catch(Exception e){
      System.out.println(e.getMessage());
    }
  }
}