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>

import java.util.Scanner;

public class MaximumCost{
    public static void main(String[] args){
        Scanner sc= new Scanner(System.in);
        double n = sc.nextInt();
        int rr = (int) Math.sqrt(n);
        double xx = Math.ceil(n/rr);
        int num = (int) (2 *((int)rr+xx));
        System.out.println(num);
    }
}
