#include <bits/stdc++.h>
using namespace std;
using ll = long long;
signed main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  ll n, st, ans;
  cin >> n;
  if (n == 1) {
    cout << 4;
    return 0;
  }
  for (ll i = 0;; ++i) {
    if (i * i <= n)
      st = i;
    else
      break;
  }
  ans = 4 * st;
  n -= (st * st);
  if (n == 0) {
    cout << ans;
    return 0;
  }
  for (int i = 1; i <= 4; ++i) {
    ans += 2;
    if (n - st <= 0) {
      break;
    }
    n -= st;
  }
  cout << ans;
  return 0;
}

### Prompt

Please formulate 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;
using ll = long long;
signed main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  ll n, st, ans;
  cin >> n;
  if (n == 1) {
    cout << 4;
    return 0;
  }
  for (ll i = 0;; ++i) {
    if (i * i <= n)
      st = i;
    else
      break;
  }
  ans = 4 * st;
  n -= (st * st);
  if (n == 0) {
    cout << ans;
    return 0;
  }
  for (int i = 1; i <= 4; ++i) {
    ans += 2;
    if (n - st <= 0) {
      break;
    }
    n -= st;
  }
  cout << ans;
  return 0;
}

```