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

class Program
{
    static void Main(string[] args)
    {
        long n = long.Parse(Console.ReadLine());
        int count = 0;

        for (int i = 1; i <= n; i++)
        {
            if (i % 3 == 0)
            {
                count += 2;
            }

            if (i % 5 == 0)
            {
                count += 2;
            }
        }

        Console.WriteLine(count);
    }
}