#include <iostream>
#include <algorithm>
#include <cmath>
#include <vector>
#include <complex>
#include <queue>
#include <deque>
#include <set>
#include <map>
#include <unordered_set>
#include <unordered_map>
#include <iomanip>
#include <assert.h>
#include <array>
#include <cstdio>
#include <cstring>
#include <random>
#include <functional>
#include <numeric>
#include <bitset>

using namespace std;

#define REP(i,a,b) for(int i=a;i<(int)b;i++)
#define rep(i,n) REP(i,0,n)
#define all(c) (c).begin(), (c).end()
#define zero(a) memset(a, 0, sizeof a)
#define minus(a) memset(a, -1, sizeof a)
#define minimize(a, x) a = std::min(a, x)
#define maximize(a, x) a = std::max(a, x)

typedef long long ll;
int const inf = 1<<29;

int main() {

  ll N; cin >> N;
  cout << N / 3 * 2 + N / 5 * 2 << endl;//+ N / 15 * 4 << endl;
/*
  int cnt = 0;
  REP(i, 1, 100) {
    if(i % 5 == 0) {
      cnt += 2;
    }
    if(i % 3 == 0) {
      cnt += 2;
    }
    cout << cnt << ", ";
  }
  cout << endl;
*/
  return 0;
}