public class World
{
             public static void main(String[] args)
             {
                       String s1="first string";
                       int a = 10;

                     System.out.println("hello world");
		 System.out.println("hello world" + a);
		 System.out.println("hello world" + "a");
		 System.out.println("hello world + a ");
		 System.out.println("hello world" + (a+2));
		 System.out.println("hello world + (a+2)");
             }
}