#include<iostream>
using namespace std;

//１５の余剰やーん
int main(void)
{
	long long int n;
	int p, k = 0, ans;

	cin >> n;
	p = n % 15;
	switch (p){
	case 1: case 2: break;
	case 3: case 4: k = 2; break;
	case 5: k = 4; break;
	case 6: case 7: case 8: k = 6; break;
	case 9: k = 8; break;
	case 10: case 11: k = 10; break;
	case 12: case 13: case 14: k = 12; break;
	default:
		break;
	} 
	ans = 16 * (int)(n / 15) + k;
	cout << ans;

	return 0;
}