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

public class ListFilterer
{
   public static IEnumerable<int> GetIntegersFromList(List<object> listOfItems)
   {
      var result = new List<int>();

      foreach (var o in listOfItems) {
        if (o is int) {
          result.Add((int) o);
        }
      }

      return result;
   }
}