using System;

using System.Collections.Generic;

using System.Collections;

​

​

class X : IEnumerable<(int, int)>

{

    private List<(int, int)> Numbers = new ();

​

    public void Add(int n, int y)

    {

        Numbers.Add((n, y));

    }

​

    IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();

​

    public IEnumerator<(int, int)> GetEnumerator() => Numbers.GetEnumerator();

}

public class Program

{

    public static void Main()

    {

        X x = new X{{1, 2}};

        Console.WriteLine("Hello World");

    }

}