#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  long long n;
  cin >> n;
  int ans = INT_MAX;
  for (int i = 1; i <= 1010; ++i) {
    for (int j = 1; j <= 1010; ++j) {
      if (i * j >= n) ans = min(ans, 2 * (i + j));
    }
  }
  cout << ans << '\n';
}

### Prompt

Please formulate a CPP solution to the following problem:

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;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  long long n;
  cin >> n;
  int ans = INT_MAX;
  for (int i = 1; i <= 1010; ++i) {
    for (int j = 1; j <= 1010; ++j) {
      if (i * j >= n) ans = min(ans, 2 * (i + j));
    }
  }
  cout << ans << '\n';
}

```