// Introduction to Software Testing
// Authors: Paul Ammann & Jeff Offutt
// Chapter 7, section 7.1, page 242

import java.util.*;

class f
{

public static void f (Stack s)
{
   String s1 = "s1";
   String s2 = "s2";
   String s3 = "s3";

   s.push (s1);
   s.push (s2);
   s.push (s3);

   g (s);

   s.pop();
   s.pop();
   // Oops! The stack is empty!
   s.pop();
   
}

public static void g (Vector v)
{
   // Remove the last element
   v.removeElementAt (v.size()-1);
}

public static void main (String []argv)
{  // Driver method for f
   // call f()
   Stack s = new Stack();

   f(s);
}

}