using System;
using System.Collections.Generic;
using System.Text;

namespace Euler1
{
    // Add all the natural numbers below one thousand that are multiples of 3 or 5.
    class Program
    {
        static void Main(string[] args)
        {
            long sum = 0;

            for(int i=0;i<1000;++i)
            {
                if( (i % 3 == 0) || (i % 5 == 0) )
                    sum += i;
            }

            Console.WriteLine("sum of all the multiples of 3 or 5 below 1000: " + sum);
        }
    }
}