using System;  

public class Exercise4  

{  

    public static void Main() 

{

    int chk_year;

    Console.Write("\n\n");

    Console.Write("Check whether a given year is leap year or not:\n");

    Console.Write("----------------------------------------------");

    Console.Write("\n\n");

    Console.Write("Input an year : ");

    chk_year= Convert.ToInt32(Console.ReadLine());

    if ((chk_year % 400) == 0)

 Console.WriteLine("{0} is a leap year.\n", chk_year);

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

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

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

 Console.WriteLine("{0} is a leap year.\n", chk_year);

    else

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

}

}

​