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.io.IOException;
import java.util.Scanner;

public class codforces {

	public static void main(String args[]) throws IOException {
    	Scanner sc = new Scanner(System.in);
    	long t = sc.nextLong();
    	long somme = 1;
    	long per ;
    	long i=2;
    	while(somme<=t){
    		if(somme==t) break;
    		somme = i*i;
    		i++;
    	}
    	
    	if(t==1){per = 4; System.out.println(per);}
    	else if(t==2){per=6;System.out.println(per);}
    	else if(t==3){ per = 8;System.out.println(per);}
    	
    	else if(somme ==t ) { i=i-1 ; System.out.println( ( i*i*4  -  i*(i-1)*4 ));}
    	else { i=i-2 ;
    		 if(t-i*i > i){ System.out.println(i*i*4  -  i*(i-1)*4 + 4);}
    		 else System.out.println(i*i*4  -  i*(i-1)*4 + 2);}
    	
    	
    	
}
}