using System;
using System.Linq;
using System.Collections.Generic;
class Program
{
///
/// プログラムのエントリポイント
///
///
static void Main(string[] args)
{
long max = long.Parse(Console.ReadLine());
var list = new List();
for (long i = 3; i <= max; i += 3)
list.Add(i);
for (long i = 5; i <= max; i += 5)
list.Add(i);
Console.WriteLine(list.Count * 2);
}
}