#include <bits/stdc++.h>
#define REP(i,a,b) for(i=a;i<b;i++)
#define rep(i,n) REP(i,0,n)

using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
/* ここからが本編 */
/*  */
int main(void)
{
  int i,j,k;
  ull n;
  ull rep = 0;
  cin >> n;
  rep = (n/3+n/5)*2;
  cout << rep << endl;
  return 0;
}