using System;

public class Program

{

    public static void Main()

    {

        Console.Write("Please enter a year: ");

        int num;

        while(!(int.TryParse(Console.ReadLine(), out num)));

        if(num % 100 == 0 && num % 400 != 0 || num % 4 != 0)

        {

            Console.WriteLine("Not a leap year");

        } else

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

    }

}