using System;

namespace No311
{
	class MainClass
	{
		public static void Main (string[] args)
		{
			var n = Convert.ToInt64(Console.ReadLine ());
			long sum = 0;
			var k = n / 15;
			sum += 4 * k;
			sum += 2 * (n / 3 - k);
			sum += 2 * (n / 5 - k);
			Console.WriteLine (sum.ToString ());
		}
	}
}