#include <iostream>		//cin, cout
#include <vector>		//vector
#include <algorithm>	//sort,min,max,count
#include <string>		//string,getline, to_string
#include <cstdlib>		//abs(int)
#include <utility>		//swap, pair
#include <deque>		//deque
#include <climits>		//INT_MAX
#include <bitset>		//bitset
#include <cmath>		//sqrt, ceil. M_PI, pow, sin

using namespace std;

int main() {

	long long int N;
	cin >> N;

	long long int ans = 0;

	for (long long int i = 1; i <= N; i++) {
		if (i % 3 == 0) {
			ans += 2;
		}
		if (i % 5 == 0) {
			ans += 2;
		}
	}
	
	cout << ans << endl;

	return 0;

}