Project Euler problem #1 solution.

using System;
using System.Linq;

public class problem
{
    static void Main()
    {
        Problem();
        Solution();
    }

    static void Problem()
    {
        Console.WriteLine("\nAdd all the natural numbers below one thousand that are multiples of 3 or 5.");
    }

    static void Solution()
    {
        int a;
        int b;

        int sum = 0;
        int cap = 1000;

        for (int i = 0; i < cap; i++)
        {
            a = i % 3;
            b = i % 5;

            if ((a == 0) || (b == 0))
                sum += i;
        }

        Console.WriteLine("\n{0}\n", sum);
    }
}