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 Main {

	public static void main(String[] args) {
		
		//System.out.println("hhhkkjhkj");
		int N =0, helper = 0, ans = 0;
		double d = 0;
		
		Scanner sc = new Scanner(System.in);
		while(sc.hasNextLine()) {
			
			N = Integer.parseInt(sc.nextLine());
			
			d = Math.sqrt(N);
			
			helper=(int) Math.round(d);
			
			if(helper > d  || helper == d )
				ans = helper * 4;
			else 
			ans = helper * 4 + 2;
			
			System.out.println(ans);
		}

	}

}
