class Queue
{
  private int[] a;
  private int head = 0;
  private int tail = 0;
  private int count = 0;
  private int N = 3;

  public Queue()
  {
    a = new int[N];
  }

  public boolean isempty()
  {
    return count == 0;
  }

  public void enqueue(int value)
  {
   if (count == a.length) resize();
   count = count+1;
   a[tail] = value;
   tail = tail+1;
   if (tail == a.length) tail = 0;
  }

  public void dequeue()
  {
    count = count-1;
    head = head+1;
  }

  public int first()
  {
    return a[head];
  }

  private void resize()
  {
    int b[] = new int[2*a.length+1];
    for (int i=head; i<a.length; i++)
      b[i-head] = a[i];
    for (int i=0; i<head; i++)
      b[i+a.length] = a[i];
    head = 0;
    tail = count;
    a = b;
  }
}