//Normal-2

#define _GLIBCXX_DEBUG
#define ll long long
#include <bits/stdc++.h>
using namespace std;
using Graph = vector<vector<int>>;

void p(auto a){
  cout << a;
}

void ps(auto a){
  cout << a << " ";
}

void ps(){
  cout << " ";
}

void pl(auto a){
  cout << a << endl;
}

void pl(){
  cout << endl;
}

void fix5(){
  cout << fixed << setprecision(5);
}

void fix10(){
  cout << fixed << setprecision(10);
}

void Yes(){
  pl("Yes");
}

void No(){
  pl("No");
}

void yes(){
  pl("yes");
}

void no(){
  pl("no");
}

//Normal-2
int main(){
  int X; cin >> X;

  vector<int> dp(20, 1e9);
  int now = 0, move = 0;
  for(int i = 0; ; i++){
    if(18 <= now) break;

    int j = i%7;
    if(j == 0 or j == 1 or j == 3){
      now += 2;
      move += 2;
    }else{
      now--;
      move++;
    }

    dp[now] = min(dp[now], move);
  }

  pl(dp[X]);
}