using System;

public class Program

{

    public static void Main()

    {

        for(int i = 0; i <= 20; i++){

            try

            {

                if(i % 4 == 0) throw new Exception("error");

                Console.WriteLine("Hello World in " + i);

            }

            catch

            {

                Console.WriteLine("error in " + i);

            }

        }       

    }

}