public class BoundedQueue
{
  private int[] a;
  private int head = 0;
  private int tail = 0;
  private int count = 0;

  public BoundedQueue(int n)
  {
    a = new int[n];
  }

  public int size()
  {
    return a.length;
  }

  public int length()
  {
    return count;
  }

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

  public int dequeue() 
  {
    count = count-1;
    int value = a[head];
    head = head+1; 
    if (head == a.length) head = 0;
    return value;
  }

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