#include <bits/stdc++.h>
using namespace std;
int get_perimetre(int n) {
  if (n == pow((floor(sqrt(n))), 2)) return floor(sqrt(n)) * 4;
  int a = floor(n - pow((floor(sqrt(n))), 2) - 1);
  int b = floor(sqrt(n));
  return (b * 4) + (((a / b) + 1) * 2);
}
int main() {
  int n, count;
  std::cin >> n;
  count = get_perimetre(n);
  std::cout << count << '\n';
  return 0;
}

### Prompt

Generate 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 get_perimetre(int n) {
  if (n == pow((floor(sqrt(n))), 2)) return floor(sqrt(n)) * 4;
  int a = floor(n - pow((floor(sqrt(n))), 2) - 1);
  int b = floor(sqrt(n));
  return (b * 4) + (((a / b) + 1) * 2);
}
int main() {
  int n, count;
  std::cin >> n;
  count = get_perimetre(n);
  std::cout << count << '\n';
  return 0;
}

```