#include<bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef long double ld;

#define rep(i, a, b) for(ll i = (ll)a; i < (ll)b; i++)
#define irep(i, v) for(auto i = (v).begin(); i != (v).end(); i++)
#define ALL(v) (v).begin(), (v).end()
#define SZ(v) (ll)(v).size()

const ll INF = 1e18;
const ld EPS = 1e-10;


int main(){
  cin.tie(0);
  ios::sync_with_stdio(false);
  srand((unsigned)time(NULL));
  cout << fixed << setprecision(20);

  ll n;
  cin >> n;

  ll ans = 0;
  ll i = 1;

  while(n > 0){
    if(i % 7 == 0) n += 6;
    n -= 1;
    ans++;
    i++;
  }
  cout << ans << endl;



  return 0;
}