#include <algorithm>
#include <climits>
#include <cmath>
#include <cstdio>
#include <cstring>
#include <functional>
#include <iostream>
#include <queue>
#include <stack>
#include <string>
#include <vector>
#define INF 10000000
#define PI 3.14159265358979323846
using namespace std;
typedef long long ll;
typedef pair<int, int> p;
typedef queue<int> qi;
typedef queue< pair<int, int> > qp;
typedef vector<int> vi;
typedef vector<int, int> vii;
typedef vector< pair<int, int> > vp;
int dx[4] = { 0, 1, 0, -1 };
int dy[4] = { 1, 0, -1, 0 };

int main(){
	ios::sync_with_stdio(false);

	ll n;
	cin >> n;
	// cout << n/3*2 << endl;
	// cout << n/5*2 << endl;

	cout << n/3*2 + n/5*2 <<endl;

	return 0;
}