// Chan-Jin Chung
class Stack
{  private int st[] = new int[100];
   private int top;
   public Stack()
   {  top = 0;
   }
   void push(int v)
   {  st[top++] = v;
   }
   int pop()
   {  return st[--top];
   }
}

public class SimpleStack
{  public static void main(String[] args)
   {  Stack s = new Stack();
      s.push(1);
      s.push(2);
      System.out.println(s.pop());
      System.out.println(s.pop());
   }
}