using System.Collections.Generic;
public static void Main()
List<int> oyears = new List<int>();
IEnumerable<int> ienum = (IEnumerable<int>)oyears;
Console.WriteLine("------------------------------");
IEnumerator<int> ienum1 = oyears.GetEnumerator();
while (ienum1.MoveNext())
Console.WriteLine(ienum1.Current);