using System;

public class Program

{

    public static void Main()

    {

            DateTime birthDate = new DateTime(2000, 2, 29);

            DateTime now = new DateTime(2009, 2, 28);

            int age = now.Year - birthDate.Year;

​

            if (now < birthDate.AddYears(age))

            //if(now <= new DateTime(birthDate.Year, birthDate.Month, birthDate.Day))

            //if (now.Month < birthDate.Month || (now.Month == birthDate.Month && now.Day < birthDate.Day))

                age--;

​

            System.Console.WriteLine(age);

    }

}