#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define INF32 2147483647
#define ALL(x) x.begin(), x.end()
vector<int> ddx = {0, 1, 0, -1, 1, 1, -1, -1};
vector<int> ddy = {1, 0, -1, 0, 1, -1, -1, 1};


int main() {
  int n;cin>>n;
  int day = 1;
  while(n != 0){
    if(day % 7 == 0){
      n += 6;
    }
    n--;
    day++;
  }
  cout<< day - 1 <<endl;
  return 0;
}