class MyStack <StackDataType> {

    StackDataType [] stack;

    int stackTop;
    
    
    // Define a constructor to initialize.
    // Note: a constructor has the same name as the class and no 
    // return type.

    public MyStack ()
    {
        stack = (StackDataType[]) new Object [100];
    }
    

    public void push (StackDataType value)
    {
        stack[++stackTop] = value;
    }
    

    public StackDataType pop ()
    {
        StackDataType value = stack[stackTop];
        stackTop --;
        return value;
    }
    

    public boolean isEmpty ()
    {
        if (stackTop < 0) {
            return true;
        }
        else {
            return false;
        }
    }

}


public class StackExample5 {

    public static void main (String[] argv) 
    {
        // Now MyStack can be defined to accept only String's.
        MyStack<String> stack = new MyStack<String> ();

        // Don't need to explicitly initialize.

        stack.push ("Alice");
        stack.push ("Bob");
        stack.push ("Chen");
        
        while (! stack.isEmpty ()) {
            // No cast required.
            String name = stack.pop ();
            System.out.println ("Removed " + name);
        }
        
    }
    
}