using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

    }

}

class MyCollection<T> : IList<T>

{

    private readonly IList<T> _list = new List<T>();

​

    #region Implementation of IEnumerable

​

    public IEnumerator<T> GetEnumerator()

    {

        return _list.GetEnumerator();

    }

​

    IEnumerator IEnumerable.GetEnumerator()

    {

        return GetEnumerator();

    }

​

    #endregion

​

    #region Implementation of ICollection<T>

​

    public void Add(T item)

    {

        _list.Add(item);

    }

​

    public void Clear()

    {

        _list.Clear();

    }

​

    public bool Contains(T item)

    {

        return _list.Contains(item);

    }

​

    public void CopyTo(T[] array, int arrayIndex)

    {

        _list.CopyTo(array, arrayIndex);

    }

​

    public bool Remove(T item)

    {

        return _list.Remove(item);

    }

​

    public int Count

    {

        get { return _list.Count; }

    }

​

    public bool IsReadOnly

    {

        get { return _list.IsReadOnly; }

    }

​

    #endregion

​

    #region Implementation of IList<T>

​

    public int IndexOf(T item)

    {

        return _list.IndexOf(item);

    }

​

    public void Insert(int index, T item)

    {

        _list.Insert(index, item);

    }

​

    public void RemoveAt(int index)

    {

        _list.RemoveAt(index);

    }

​

    public T this[int index]

    {

        get { return _list[index]; }

        set { _list[index] = value; }

    }

​

    #endregion

​

    #region Your Added Stuff

​

    // Add new features to your collection.

​

    #endregion

}