static IEnumerable<T> Generator<T>(Func<int, T> gen, Func<T, bool> func)
        {
            var i = 0;
            while (true)
            {
                var x = gen(i);
                i++;
                if (!func(x))
                {
                    break;
                }
                yield return x;
            }
        }
        static void Main(string[] args)
        {
            DateTime dt = new DateTime(2019, 11, 29);
            DateTime last = new DateTime(2028, 09, 15);

            var res = Generator(x => dt.AddDays(x), x => x <= last)
                .Count(x => DateTime.IsLeapYear(x.Year));


            Console.ReadLine();


        }