using System;
using System.Collections;
using System.Collections.Generic;

namespace IteratorExample
{
    public class OneToTen : IEnumerable<int>
    {
        public IEnumerator<int> GetEnumerator()
        {
            for (int i = 1; i <= 10; i++)
            {
                yield return i;
            }
        }

        IEnumerator IEnumerable.GetEnumerator()
        {
            return GetEnumerator();
        }
    }
    class Program
    {
        static void Main(string[] args)
        {
            OneToTen ott = new OneToTen();
            foreach (int i in ott)
            {
                Console.WriteLine(i);
            }
            Console.ReadLine();
        }
    }
}