#include <bits/stdc++.h>
using namespace std;
using ll = long long int;
using vi = vector<int>;
using vvi = vector<vi>;
using vll = vector<ll>;
using vvll = vector<vll>;
const int maxsq = 1009;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  int n;
  cin >> n;
  int sq = 1;
  for (;; ++sq) {
    if (sq * sq >= n) break;
  }
  int ans = 4 * sq + 2 * ((n - sq * sq) / sq);
  cout << ans << endl;
}

### Prompt

Please provide a CPP coded solution to the problem described below:

Your security guard friend recently got a new job at a new security company. The company requires him to patrol an area of the city encompassing exactly N city blocks, but they let him choose which blocks. That is, your friend must walk the perimeter of a region whose area is exactly N blocks. Your friend is quite lazy and would like your help to find the shortest possible route that meets the requirements. The city is laid out in a square grid pattern, and is large enough that for the sake of the problem it can be considered infinite.

Input

Input will consist of a single integer N (1 ≤ N ≤ 106), the number of city blocks that must be enclosed by the route.

Output

Print the minimum perimeter that can be achieved.

Examples

Input

4


Output

8


Input

11


Output

14


Input

22


Output

20

Note

Here are some possible shapes for the examples:

<image>

### Response

```cpp
#include <bits/stdc++.h>
using namespace std;
using ll = long long int;
using vi = vector<int>;
using vvi = vector<vi>;
using vll = vector<ll>;
using vvll = vector<vll>;
const int maxsq = 1009;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  int n;
  cin >> n;
  int sq = 1;
  for (;; ++sq) {
    if (sq * sq >= n) break;
  }
  int ans = 4 * sq + 2 * ((n - sq * sq) / sq);
  cout << ans << endl;
}

```