#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  int i = 1;
  for (; i <= n; i++) {
    if (i * i > n) {
      i--;
      break;
    }
  }
  if (n == 1) {
    cout << 4;
    return 0;
  }
  if (i * i == n) {
    cout << i + i + i + i;
    return 0;
  }
  int sum = 0;
  sum = i * 4;
  n -= i * i;
  int z = n / i;
  sum += z * 2;
  if (n > i * z) {
    sum += 2;
  }
  cout << sum;
}

### Prompt

Construct a cpp code solution to the problem outlined:

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 i = 1;
  for (; i <= n; i++) {
    if (i * i > n) {
      i--;
      break;
    }
  }
  if (n == 1) {
    cout << 4;
    return 0;
  }
  if (i * i == n) {
    cout << i + i + i + i;
    return 0;
  }
  int sum = 0;
  sum = i * 4;
  n -= i * i;
  int z = n / i;
  sum += z * 2;
  if (n > i * z) {
    sum += 2;
  }
  cout << sum;
}

```