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

namespace FibonacciTest
{
    public class Program
    {
        public static void Main()
        {
            foreach (var i in FibonacciGeneratorTwo.Fibonacci().Take(10))
            {
                Console.WriteLine(i);
            }
        }
    }

    internal static class FibonacciGeneratorTwo
    {
        public  static IEnumerable<int> Fibonacci()
        {
            int current = 1, next = 1;
            while (true)
            {
                yield return current;
                next = current + (current = next);
            }
        }
    }
}