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

namespace yukicord311
{
	class Program
	{
		static void Main(string[] args)
		{
			long N = Int64.Parse(Console.ReadLine());

			Console.WriteLine(((N / 5) + (N / 3)) * 2);
			Console.ReadKey();
		}
	}
}