using System;
using System.Linq;

class Program
{
    static void Main(string[] args)
    {
        long N = long.Parse(Console.ReadLine());

        long fb = N / 15;
        long f = N / 3 - fb;
        long b = N / 5 - fb;

        Console.WriteLine((fb * 4) + ((f + b) * 2));
    }
}