using System;

public class Program

{

    public static void Main()

    {

        int chkYear;

        Console.WriteLine("Check whether a given year is a leap year or not");

        Console.WriteLine("........................................................");

        bool finish = false;

        do

        {

        Console.WriteLine("Enter the year you want to check (or 0 to end)");

            chkYear= Convert.ToInt16(Console.ReadLine());

        if (chkYear == 0)

        {

            finish = true;

            Console.WriteLine("All done");

        }

            else if  ((chkYear %400)==0)

            {

            Console.WriteLine("{0} is a leap year", chkYear);

            }

            else if ((chkYear%100)==0)

            {

                Console.WriteLine("{0} is not a leap year", chkYear);

            }

            else if ((chkYear %4)==0)

            {

                Console.WriteLine("{0} is a leap year" ,  chkYear);

            }

            else

            {

            Console.WriteLine("{0} is not a leap year", chkYear);

            }

            }

            while (!finish);

    }

}

​