interface ExceptionDemo
{ String compute(String s) throws NullPointerException; }

class DemoOfLambdaException
{   public static void main(String[] args)
	{
		ExceptionDemo ed = (str) -> {
		if(str.length()==0 || str==null)
			throw new NullPointerException("No String is available");
		else
			return "The string "+str+" has "+str.length()+" characters.";
	};
	
	java.util.Scanner scan = new java.util.Scanner(System.in);
	System.out.println("Enter a String: ");
	String s = scan.nextLine();
	System.out.println(ed.compute(s));
	}
}