#include <cstdio>
#include <cmath>
#include <cstring>
#include <iostream>
#include <iomanip>
#include <sstream>
#include <map>
#include <set>
#include <array>
#include <queue>
#include <string>
#include <vector>
#include <numeric>
#include <algorithm>
#include <functional>
#define MOD 1000000007
#define INF 11234567890
#define in std::cin
#define out std::cout
#define rep(i,N) for(LL i=0;i<N;++i)
typedef long long int LL;
typedef std::pair<int, int> P;

LL N;
LL ans;

int main()
{
	in >> N;

	for (LL i = 1; i <= N; ++i)
	{
		if (i % 3 == 0)
		{
			ans += 2;
		}
		if (i % 5 == 0)
		{
			ans += 2;
		}
	}

	out << ans << std::endl;
	return 0;
}