using System;
using System.Collections.Generic;
using System.Linq;

public class yukicoder
{
    public static void Main()
    {
        decimal n = decimal.Parse(Console.ReadLine());
        decimal zcount = 0;

        for (decimal i = 1; i <= n; i++)
        {
            if (i % 3 == 0 && i % 5 == 0)
            {
                zcount = zcount + 4;
            }
            else if (i % 3 == 0 || i % 5 == 0)
            {
                zcount = zcount + 2;
            }
        }

        Console.WriteLine(zcount);

    }
}