import java.util.Scanner;
public class MyArrayUnBndQueue<T> {
    public static final int INITIAL_CAPACITY = 3;
    private T[] queue = (T[]) new Object[INITIAL_CAPACITY];
    private int numElts = 0;
    private int front = 0;
    private int rear = queue.length-1;
  
    public T dequeue() throws Exception {
	if (isEmpty())
	    throw new Exception ("Dequeue on empty Q");
	numElts--;
	T ans = queue[front];
	front = (front+1) % queue.length;
	return ans;
    }

    public void enqueue(T elt) throws Exception {
	if (numElts == queue.length)
	    enlarge();
	numElts++;
	rear = (rear+1) % queue.length;
	queue[rear] = elt;
    }

    public boolean isEmpty() { return numElts == 0; }

    private void enlarge() {
	T[] doubleQ = (T[]) new Object[2*queue.length];
	for (int i=0; i<queue.length; i++) {
	    doubleQ[i] = queue[front];
	    front = (front + 1) % queue.length;
	}
	queue = doubleQ;
	front = 0;
	rear = numElts-1;
    }

    // The class should end here.  Main program from end of 5.2

    public static void main (String[] args) throws Exception {
	Scanner getInput = new Scanner(System.in);
	String str;
	MyArrayUnBndQueue<Integer> queue = new MyArrayUnBndQueue<Integer>();
	while (!(str=getInput.next()).equals("done"))
	       if (str.equals("enqueue"))
		   queue.enqueue(getInput.nextInt());
	       else if (str.equals("dequeue"))
		   System.out.println(queue.dequeue());
	       else
		   System.out.println("Illegal!");
    }
}
// Local Variables:
// c-basic-offset: 4
// compile-command: "javac -Xlint:unchecked MyArrayUnBndQueue.java && \
//                   java MyArrayUnBndQueue < input.text"
// End: