#include <bits/stdc++.h>
using namespace std;
int main() {
  int ans = 1e9;
  int x;
  scanf("%d", &x);
  int s = sqrt(1000000);
  for (int i = 0; i <= s; ++i) {
    for (int j = 0; j <= s; ++j) {
      if (i * j >= x) {
        ans = min(ans, i * 2 + j * 2);
      }
    }
  }
  printf("%d\n", ans);
}

### Prompt

Develop a solution in CPP 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;
int main() {
  int ans = 1e9;
  int x;
  scanf("%d", &x);
  int s = sqrt(1000000);
  for (int i = 0; i <= s; ++i) {
    for (int j = 0; j <= s; ++j) {
      if (i * j >= x) {
        ans = min(ans, i * 2 + j * 2);
      }
    }
  }
  printf("%d\n", ans);
}

```