#include <bits/stdc++.h>
using namespace std;
vector<int> vec[1001];
vector<bool> vis;
int main() {
  int tc, cse = 0;
  {
    int n;
    cin >> n;
    int sqt = sqrt(n);
    int total = sqt * 4;
    int rem = n - (sqt * sqt);
    int rem1 = rem / sqt;
    if (rem % sqt) rem1++;
    total += rem1 * 2;
    cout << total << endl;
  }
}

### Prompt

Your challenge is to write 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;
vector<int> vec[1001];
vector<bool> vis;
int main() {
  int tc, cse = 0;
  {
    int n;
    cin >> n;
    int sqt = sqrt(n);
    int total = sqt * 4;
    int rem = n - (sqt * sqt);
    int rem1 = rem / sqt;
    if (rem % sqt) rem1++;
    total += rem1 * 2;
    cout << total << endl;
  }
}

```