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

namespace YukiCoder
{
    class Program
    {
        static void Main(string[] args)
        {
            long nn = long.Parse(Console.ReadLine());
            Console.WriteLine((nn / 3 + nn / 5) * 2);
            Console.ReadLine();
        }
    }
}