#include <iostream>

using namespace std;

static constexpr int FizzNum = 2;
static constexpr int BuzzNum = 2;
static constexpr int FizzBuzzNum = 4;

int main()
{
    unsigned long long v = 0;    
    cin >> v;
    
    cout << ( ( v / 3 ) * 2 +  ( v / 5 ) * 2 ) << endl;
}