#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  int a, b, c;
  a = sqrt(n);
  b = (n - (a * a));
  c = b / a;
  int ans = 0, d, e;
  ans = a + c;
  d = b % a;
  if (d > 0)
    ans = 2 * (a + a + c) + 2;
  else
    ans = 2 * (a + a + c);
  cout << ans;
  return 0;
}

### Prompt

In Cpp, your task is to solve 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() {
  int n;
  cin >> n;
  int a, b, c;
  a = sqrt(n);
  b = (n - (a * a));
  c = b / a;
  int ans = 0, d, e;
  ans = a + c;
  d = b % a;
  if (d > 0)
    ans = 2 * (a + a + c) + 2;
  else
    ans = 2 * (a + a + c);
  cout << ans;
  return 0;
}

```