using System;
using System.Linq;

class No311{
    static void Main(){
        var num=Int64.Parse(Console.ReadLine());
        var count=0;
        for(long i=0;i<num;++i){
            if(i%3==0)count+=2;
            if(i%5==0)count+=2;
        }
        Console.WriteLine(count);
    }
}