class Queue
{
    private items = [];

    public Enqueue(val)
    {
        items.Add(val);
    }

    public Dequeue()
    {
        if(items.Count == 0) return null;
        const val = items[0];
        items.RemoveAt(0);

        return val;
    }

    public Peek()
    {
        if(items.Count == 0) return null;
        return items[0];
    }

    public GetEnumerator()
    {
        return items.GetEnumerator();
    }

    public getCount() items.Count;
    public getLength() items.Length;
}