Driver.java

import java.io.*;
import java.util.*;

public class Driver {

    public static void main(String[] args) {        
	Greeter g,g2;
	g = new Greeter();
	g2 = new Greeter();
	System.out.println(g.sadGreet("Tom"));
	System.out.println(g2.happyGreet("Tom"));
    }
}