#include <bits/stdc++.h>
using namespace std;
using ll = long long;
ll a[1000005];
set<ll> s;
void solve() {
  ll n, x, y, rest, ans = 0;
  cin >> n;
  for (ll i = 1; i * i <= n; i++) x = i;
  y = n / x;
  rest = n - (x * y);
  if (rest == 0)
    ans += ((2 * x) + y) + (y - rest);
  else
    ans += ((2 * x) + y) + (y - rest) + (rest + 2);
  cout << ans << endl;
  return;
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  solve();
  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;
ll a[1000005];
set<ll> s;
void solve() {
  ll n, x, y, rest, ans = 0;
  cin >> n;
  for (ll i = 1; i * i <= n; i++) x = i;
  y = n / x;
  rest = n - (x * y);
  if (rest == 0)
    ans += ((2 * x) + y) + (y - rest);
  else
    ans += ((2 * x) + y) + (y - rest) + (rest + 2);
  cout << ans << endl;
  return;
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  solve();
  return 0;
}

```