using System;

using System.Collections.Generic;

using  System.Linq;

​

public class Program

{

    public static void Main()

    {

        var value = 0; 

        for(var ii = 1; ii < 1000; ii++)

        {

            if(ii % 3 == 0 || ii % 5 == 0)

            {

                value += ii; 

            }

        }

        Console.WriteLine(value);

    }

}