using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Enter year");

        int year=int.Parse(Console.ReadLine());

        if (DateTime.IsLeapYear(year))

            {

                Console.WriteLine("This is a leap year.");

            }

            else

            {

                Console.WriteLine("This is not a leap year.");

            }

    }

}