using System;

public class Program

{

    public static void Main()

    {

        int num,evennum=0;

        Console.WriteLine("Enter number of your choice");

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

        for(int i=2;i<=num;i+=2)

        {

            evennum+=i;

        }

        Console.WriteLine("Sum of Even Numbers are {0}",evennum);

    }

}