#include<bits/stdc++.h>
using namespace std;

#define int      long long
#define all(xs)   xs.begin(), xs.end()
#define make_unique(x) sort(all((x))); (x).resize(unique(all((x))) - (x).begin())

signed main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int x;
  cin >> x;
  int x1 = 0;
  int ans = 0;
  vector<int> a = {2 , 2 , -1 , -1 , 2 , -1 , -1};
  for (int i = 0; ; i = (i + 1) % 7) {
    x1 += a[i];
    ans += abs(a[i]);
    if (x1 == x) {
      break;
    }
  }
  cout << ans;
}